Did my crazy husband's experiments keep you up all night?
Experiments upon this subject are not difficult.
Berzelius, and somewhat later, in the experiments of the Belgian chemist J.
One of these experiments may be described.
Quinn could poke around with his experiments on his own time as he'd done all summer.
You can't trust the good guys, because they'll use you for science experiments, and the bad guys put you in Hell.
Farming will be done on such a scale that thousands of experiments can be happening at any one time, putting a tiny fraction of the produce at risk.
Another of Ully's experiments. Hopefully it's better than his demon skunk spray.
Laura Bridgman was born at Hanover, New Hampshire, December 21, 1829; so she was almost eight years old when Dr. Howe began his experiments with her.
Here in Dr. Bell's laboratory, or in the fields on the shore of the great Bras d'Or, I have spent many delightful hours listening to what he had to tell me about his experiments, and helping him fly kites by means of which he expects to discover the laws that shall govern the future air-ship.
As she did every day, she went to the table near his cluttered desk to await her blood draw and any other experiments he wanted to do.
He had just constructed a boat that could be propelled by a kite with the wind in its favor, and one day he tried experiments to see if he could steer the kite against the wind.
I'd like space to do some independent experiments too.
Essentially, we will be able to run as many controlled experiments as we can imagine instantly and for no cost—and that will revolutionize medicine.
All experiments are fruitful if you don't have any preconceived notions about the results.
The aurists then tried their experiments with quite different results.
The human race is interested in these experiments, though a few old women who are incapacitated for them, or who own their thirds in mills, may be alarmed.
Something about science experiments, Megan said, poking her head in.
The machine will figure this out as it collects more data and incorporates more variables, and then experiments on people to see which combinations of factors work the best.
Gerdien has more recently repeated the experiments, employing an apparatus devised by him for the purpose.
Of late years many experiments have been made on the influence of electric fields or currents on plant growth.
The best-known of Joule's experiments was that in which a brass paddle consisting of eight arms rotated in a cylindrical vessel of water containing four fixed vanes, which allowed the passage of the arms of the paddle but prevented the water from rotating as a whole.
According to his notes, far more experiments were conducted than were ever discussed with us.
There is some reason to hope that the day of these misconceptions is passed; although there is also some reason to fear that on other grounds the present era may be known to posterity as an era of instrumentation comparable, in its gorgeous chaos of experiment and its lack of consistent ideas of harmony and form, only to the monodic period at the beginning of the 17th century, in which no one had ears for anything but experiments in harmonic colour.
In each of a number of experiments he found that the weight of the silver iodide did not differ by one twenty-thousandth of the whole from the sum of the weights of the silver and the iodine used.
P. Reeves, State Experiments in Australia and New Zealand; A.
It gives name to a school of gunnery, where officers are instructed and experiments carried out.
Brown, who described experiments which were in disagreement with Pasteur's dictum.
Several experiments were tried, to determine positively whether or not she had any perception of sound.
The third room is filled with my wizard mad scientist husband's electronic hub bub of messy experiments.
Quinn seemed relieved no one was blaming him or his experiments.
She shook her head, not sharing his excitement about his experiments.
It was not until the middle of the 18th century that experiments due to Benjamin Franklin showed that the electric phenomena of the atmosphere are not fundamentally different from those produced in the laboratory.
His wisdom grew mainly out of his own reflections and experiments.
Ramsay, repeating these experiments, found that the inert gas emitted refused xIIl.
S., is famous in connexion with the socialist experiments of Robert Owen.
The results of these first experiments were not encouraging, owing mainly to the poor class of animals, but the exporters persevered, and the business steadily grew in value and importance, until in 1898 the number of live cattle shipped was 359,296, which then decreased to 119,189 in 1901, because of the foot-and-mouth disease.
The department of agriculture has an experiment station, established by the state in 1896, in which important experiments in cotton breeding have been carried on.
"It is hardly necessary to add," he remarks, "that anything which any insulated body or system of bodies can continue to furnish without limitation cannot possibly be a material substance; and it appears to me to be extremely difficult, if not quite impossible, to form any distinct idea of anything capable of being excited and communicated in the manner that heat was excited and communicated in these experiments, except it be motion."
P. Joule to achieve; his experiments conclusively prove that heat and energy are of the same nature, and that all other forms of energy can be transformed into an equivalent amount of heat.
He also determined a roughly approximate value for the mechanical equivalent of heat from the results of these experiments.
In such experiments the molecular energy of a gas is converted into work only in virtue of the molecules being separated into classes in which their velocities are different, and these classes then allowed to act upon one another through the intervention of a suitable heat-engine.
Elec. Eng., 2 7, p. 869.) In 1899 experiments were made atMenai Straits to put the lighthouse at the Skerries into communication with the coastguard station at Cemlyn.
Hughes made some remarkable observations and experiments in or between the years 1879 and 1886 though he did not describe them till some twenty years afterwards.
Marconi's earliest experiments with this apparatus were made in Italy.
Some of these experiments were made on Salisbury Plain and others in the Bristol Channel between Lavernock and Flat Holm and Bream Down in 1897.
This transmitting plant was completed in December 1901, and Marconi then crossed the Atlantic to Newfoundland and began to make experiments to ascertain if he could detect the waves emitted by it.
In the same year numerous experiments were tried with the assistance of an Italian battleship, the " Carlo Alberto," lent by the Italian government, and messages were transmitted from Poldhu to Kronstadt, to Spezia, and also to Sydney in Nova Scotia.
Experiments precisely analogous!
in length by any mirrors which can be practically constructed would be like attempting optical experiments with mirrors one-hundred-thousandth of an inch in diameter.
Experiments bearing on this subject were subsequently made by a great number of investigators.4 Page's discovery is of considerable importance in connexion with the theory of action of various forms of telephone, and was a very important feature in the early attempts by Reis to transit music and speech.
The suggestion of Bourseul and the experiments of Reis are founded on the idea that a succession of currents, corresponding in number to the successive undulations of the pressure on the membrane of the transmitting instrument, could reproduce at the receiving station sounds of the same character as those produced at the sending station.
The experiments with this form were not successful, and, with the view of making the moving parts as light as possible, he substituted for the comparatively heavy lever armature a small piece of clock spring, about the size of a sixpence, glued to the centre of the diaphragm.
This answered sufficiently well to prove the feasibility of the plan, and subsequent experiments were directed to the discovery of the best form and arrangement of the parts.
A cylinder of chalk was used in some of Edison's later experiments with this receiver.
Experiments very similar to these of Edison were made by Elisha Gray of Boston, Mass., and described by him in papers communicated to the American Electrical Society in 1875 and 1878.
In these experiments the electric current passed through the fingers of the operator's hand, which thus took the place of the spring in Edison's apparatus.
Hughes, while engaged in experiments upon a Bell telephone in an electric circuit, discovered that a peculiar noise was produced whenever two hard electrodes, such as two wires, were - drawn across each other, or were made to touch each other with a variable degree of firmness.
Gaine, general manager of the company, stated before the Select Committee that in the view of the directors the bargain was a hard one, because it gave no consideration in respect of the goodwill of the great business, with its gross income of over £ 2,000,000 per annum and its net revenue of over £750,000, which the company had built up. The company had had to pay for all the experiments and mistakes which are inherent in the launching and development of any new industry.
There are now four circuits between London and Paris, one between London and Lille, and two between Londofi and Brussels, the last carrying an increasing amount of traffic. Experiments have been made in telephonic communication between London and Rome by way of Paris.
Experiments hitherto made show that the cultivation of Oriental tobacco may.
Before proposing the reintroduction of the tax, Sella and his friend Ferrara improved and made exhaustive experiments with the meter.
Many experiments point to certain small grains of starch which are capable of displacement as the position of the cell is altered.
The result of experiments conducted by Dr Marloth (Trans.
In 1826 the idea occurred to him of attacking this problem by means of pendulum experiments at the top and bottom of a deep mine.
The experiments eventually took place at the Harton pit near South Shields in 1854.
Amongst the most important of his works not already mentioned may be named the following: - Mathematical Tracts (1826) on the Lunar Theory, Figure of the Earth, Precession and Nutation, and Calculus of Variations, to which, in the second edition of 1828, were added tracts on the Planetary Theory and the Undulatory Theory of Light; Experiments on Iron-built Ships, instituted for the purpose of discovering a correction for the deviation of the Compass produced by the Iron of the Ships (1839); On the Theoretical Explanation of an apparent new Polarity in Light (1840); Tides and Waves (1842).
They thought that it was not sufficient to trust to the ear alone, to determine the principles of music, as did practical musicians like Aristoxenus, but that along with the ear, physical experiments should be employed.
In order to explain the course of the revolution which came to a head in 1905 it is necessary to say a few words about constitutional plans and liberal experiments, initiated from above, which had preceded it.
The draw-bar pull for a given load is a function of the speed of the train, and numerous experiments have been made to find the relation connecting the pull with the speed under various conditions.
A series of experiments were made by J.
p. 1275), by Barbier, for some experiments made on the Northern railway of France with a train of 157 tons mean weight; they are valid between 37 and 77 m.
From Aspinall's experiments it appears to be about 17 lb per ton, and this value is plotted on the diagram.
A general result could not be obtained, even from a large number of experiments, because the resistance round curves depends upon so many variable factors.
Eng., October 1898), it appeared that the engine resistance was about 35% of the total resistance, and in the train-resistance experiments on the Lancashire & Yorkshire railway quoted above the engine resistance was also about 35% of the total resistance, thus confirming the North-Eastern railway results.
17, together with a curve expressing generally the results of some early experiments on the Great Western railway carried out by Sir D.
The first group consists of experiments selected from the records of a large number made on the boiler of the locomotive belonging to the Purdue University, Indiana, U.S.A.
The second group consists of experiments made on a boiler belonging to the Great Eastern Railway Company.
The first one of the group was made on the boiler fixed in the locomotive yard at Stratford, and the two remaining experiments of the group were made while the engine was working a train between London and March.
The third group consists of experiments selected from the records of a series of trials made on the London & South-Western railway with an express locomotive.
in Professor Goss's experiments, was 1 72 in.
22 represents the thermal efficiency actually obtained in one of Adams and Pettigrew's experiments, namely, 0-I I, the pressure in the steam-pipe being 167 lb per square inch.
Lines representing efficiency ratios of o 6, 0.5 and 0.4 are plotted on the diagram, so that the efficiency ratios corresponding to the various experiments plotted may be readily read off.
The experiments of S.
For instance, it is not very uncommon to find persons who can make loud sounds by partially dislocating and restoring the toe, knee, or other joints, and some experiments made with the Fox girls in 1851 supported the view that they made raps by this method.
ing, there is no good evidence that such experiments have ever succeeded.
Count Agenor de Gasparin, in his Tables tournantes (Paris, 1854), gives an account of what seem to have been careful experiments, though they are hardly described in sufficient detail to enable us to form an independent judgment.
The experiments were conducted with his own family and friends without professional mediums, and in some of them he was assisted by M.
Sir William Crookes has published accounts of striking experiments and observations with D.
Experiments in protection on a larger scale, and under more ordinary conditions, have been carried out with equal success by Professor Celli and other Italian authorities.
In 1900 further experiments gave still better results.
Out of a total of 207 persons protected in these railway experiments, 197 escaped.
These and other experiments, described by Dr Manson in the Practitioner for March 1900, confirming the laboratory evidence as they do, leave no doubt whatever of the correctness of the mosquito-parasitic theory of malaria.
When a place cannot be kept free from mosquitoes the house may be protected, as in the experiments in Italy, by wire gauze at the doors and windows.
Experiments in immunizing by sero-therapeutic methods have not as yet met with success.
His thermochemical work was begun in 1853, but most of his experiments were performed in the years 1869-82, the whole being published collectively, under the title Thermochemische Untersuchungen, in four volumes.
With the death of Schwarzenberg in 1852 the personal government of the emperor really began, and with it that long series of experiments of which Austria has been the subject.
Recent experiments lead to the conclusion that iron, lead, manganese, lignite and sulphur exist in considerable abundance.
The first dictator is said to have been created in 501 B.C.; the last of the " administrative " dictators belongs to the year 216 B.C. It was an office that was incompatible both with the growing spirit of constitutionalism and with the greater security of the city; and the epoch of the Second Punic War was marked by experiments with the office, such as the election of Q.
Recent experiments by A.
Lubbock's experiments of inLlucing ants to seek objects that had been removed show that they are guided by scent rather than by sight, and that any disturbance of their surroundings often causes great uncertainty in their actions.
Lubbock goes so far as to conclude the account of his experiments with the remark that " It is difficult altogether to deny them the gift of reason ...
Morgan sums up a discussion on Lubbock's experiments in which the ants failed to utilize particles of earth for bridge-making, with the suggestive remark that " What these valuable experiments seem to show is that the ant, probably the most intelligent of all insects, has no claim to be regarded as a rational being."
Wheat has been produced in some localities, but not on a paying basis, and experiments have also been made with tea.
The most important subjects of his inquiries are enumerated by Forbes under the following five heads: - (1) The laws of polarization by reflection and refraction, and other quantitative laws of phenomena; (2) The discovery of the polarizing structure induced by heat and pressure; (3) The discovery of crystals with two axes of double refraction, and many of the laws of their phenomena, including the connexion of optical structure and crystalline forms; (4) The laws of metallic reflection; (5) Experiments on the absorption of light.
He spent his time in making chemical experiments and in speculating upon legal abuses, rather than in reading Coke upon Littleton and the Reports.
It was about this time that the first experiments were made (in Germany) with basic slag, a material which had hitherto been regarded as a worthless by-product of steel manufacture.
Experiments on an actual course of rotation, without manure, and with different manures, have also been made.
Amongst the field experiments there is, perhaps, not one of more universal interest than that in which wheat was grown for fifty-seven years in succession, (a) without manure, (b) with farmyard manure and (c) with various artificial manures.
Hall, Book of the Rothamsted Experiments (1905).
Experiments upon the growth of barley for fifty years in succession on rather heavy ordinary arable soil resulted in showing that the produce by mineral manures alone is larger than that without manure; that nitrogenous manures alone give more produce than mineral manures alone; and that mixtures of mineral and nitrogenous manure give much more than either used alone - generally twice, or more than twice, as much as mineral manures alone.
The average results show that, under all conditions of manuring - excepting with farmyard manure - the produce was less over the later than over the earlier periods of the experiments, an effect partly due to the seasons.
Experiments similar to the foregoing were carried on for many years in succession at Rothamsted upon oats, and gave results which were in general accordance with those on the other cereal crops.
Additional significance to the value of the above experiments on wheat and barley is afforded by the fact that the same series, with but slight modifications, has also been carried out since 1876 at the Woburn (Bedfordshire) experimental farm of the Royal Agricultural Society of England, the soil here being of light sandy character, and thus very different from the heavy soil of Rothamsted.
- Experiments upon root-crops--chiefly white turnips, Swedish turnips (swedes) and mangels - have resulted in the establishment of the following conclusions.
The field experiments on leguminous plants at Rothamsted have shown that land which is, so to speak, exhausted so far as the growth of one leguminous crop is concerned, may still grow very luxuriant crops of another plant of the same natural order, but of different habits of growth, and especially of different character and range of roots.
Considering that the results of Hellriegel and Wilfarth on this point were, if confirmed, of great significance and importance, it was decided to make experiments at Rothamsted on somewhat similar lines.
Further experiments relating to certain aspects of the subject were begun in 1898.
In the feeding experiments which have been carried on at Rothamsted it has been shown that the amount consumed both for a given live weight of animal within a given time, and for the production of a given amount of increase, is, as current food-stuffs go, measurable more by the amounts they contain of digestible and available non-nitrogenous constituents than by the amounts of the digestible and available nitrogenous constituents they supply.
In 1 In the absence of experiments it is assumed that wheat is digested like other foods of the same class.
In the year 1904-1905 £10,600 was devoted by the Board of Agriculture to agricultural instruction and experiments.
The county councils also expend sums varying at their own discretion on instruction in dairy-work, poultry-keeping, farriery and veterinary science, horticulture, agricultural experiments, agricultural lectures at various centres, scholarships at, and grants to, agricultural colleges and schools; the whole amount in 1904-1905 reaching £87,472.1 The sum spent by individual counties varies considerably.
He conducted experiments to show that certain abstract forms and proportions are naturally pleasing to our senses, and gave some new illustrations of the working of aesthetic association.
Robert Boyle, who turned his skill to account in the construction of his air-pump. On the 12th of November 1662 he was appointed curator of experiments to the Royal Society, of which he was elected a fellow in 1663, and filled the office during the remainder of his life.
In 1758 he obtained a more congenial congregation at Nantwich, where he opened a school at which the elementary lessons were varied with experiments in natural philosophy.
Trans., 1772) described experiments which showed that growing plants are able to "restore" air which has been vitiated, whether by being breathed or by having candles burnt in it.
Priestley displayed much ingenuity in devising apparatus suited to his requirements and in carrying out and varying his experiments; it was in the interpretation of results that he was deficient.
His chief books on chemistry were six volumes of Experiments and Observations on different Kinds of Air, published between 1774 and 1786; Experiments on the Generation of Air from Water (1793) Experiments and Observations relating to the Analysis of Atmospheric Air, and Considerations on the Doctrine of Phlogiston established and that of the Composition of Water refuted (1800).
The city owes its origin to a series of commercial experiments.
Probably by unconscious selection of surviving plants through long ages this type has been evolved in Guatemala, and experiments have been made to develop weevil-resistant races in the United States.
When selection is being made for several characters at the same time, and also in hybridization experiments, where it is important to have full records of the characters of individual plants and their progeny, " score cards," such as are used in judging stock, with a scale of points, are used.
Special interest attaches to experiments made in the United States to endeavour to raise races of cotton resistant to the boll weevil.
In 1900 the Imperial Department of Agriculture and private planters began experiments with the object of reintroducing the cultivation, owing to the decline in value of sugar.
One great object of their experiments was to introduce and acclimatize exotic cottons.
Still more recently, however, experiments have been made to grow Egyptian cotton in Sind with the help of irrigation.
As early as 1804, Humboldt expressed the opinion that petroleum was produced by distillation from deep-seated strata, and Karl Reichenbach in 1834, suggested that it was derived from the action of heat on the turpentine of pine-trees, whilst Brunet, in 1838, adumbrated a similar theory of origin on the ground of certain laboratory experiments.
Berthelot was the first to suggest, in 1866, after conducting a series of experiments, that mineral oil was produced by purely chemical action, similar to that employed in the manufacture of acetylene.
Peckham, but others have held that it is of exclusively animal origin, a view supported by such occurrences as those in the orthoceratities of the Trenton limestone, and by the experiments of C. Engler, who obtained a liquid like crude petroleum by the distillation of menhaden (fish) oil.
The result of this treatment is that the comparatively heavy oils undergo dissociation, as shown by the experiments of Thorpe and Young, into specifically lighter hydrocarbons of lower boiling points, and the yield of kerosene from ordinary crude petroleum may thus be greatly increased.
The land is poor in minerals, including coal; water-power also is deficient, so that the introduction of European industries is attended with difficulties even apart from the insecurity of affairs, which forbids such experiments as the improvement of agriculture by means of European capital.
His versatility was shown in his organization of the Army Works Corps which served in the Crimea, his excellent capacity as a man of business in railway management, and his enterprising experiments in floriculture.
Though an alchemist, Boyle, in his Sceptical Chemist (1661), cast doubts on the " experiments whereby vulgar Spagyrists are wont to endeavour to evince their salt, sulphur and mercury to be the true principles of things," and advanced towards the conception of chemical elements as those constituents of matter which cannot be further decomposed.
So late as 1782, James Price, an English physician, showed experiments with white and red powders, by the aid of which he was supposed to be able to transform fifty and sixty times as much mercury into silver and gold.
The metals he produced are said to have proved genuine on assay; when, however, in the following year he was challenged to repeat the experiments he was unable to do so and committed suicide.
Metallurgical operations, such as smelting, roasting, and refining, were scientifically investigated, and in some degree explained, by Georg Agricola and Carlo Biringuiccio; ceramics was studied by Bernard Palissy, who is also to be remembered as an early worker in agricultural chemistry, having made experiments on the effect of manures on soils and crops; while general technical chemistry was enriched by Johann Rudolf Glauber.1
was primarily based upon certain experiments on combustion and calcination, and in effect reduced the number of the alchemical principles, while setting up a new one, a principle of combustibility, named phlogiston (from (PXoyun-6s, burnt).
The principles outlined above constitute the foundations of our science; and although it may happen that experiments may be made with which they appear to be not in complete agreement, yet in general they constitute a body of working hypotheses of inestimable value.
The success which attended his experiments in the case of silicon led him to apply it to the isolation of other elements.
Experiments showed that the second acid was much more difficult to esterify than the first, pointing to the conclusion that Claus' formula for benzene was more probable than Kekule's.
In his earlier experiments he burned the substance in a known volume of oxygen, and by measuring the residual gas determined the carbon and hydrogen.
In 1766 he was apprenticed to a storekeeper at Salem, in New England, and while in that employment occupied himself in chemical and mechanical experiments, as well as in engraving, in which he attained to some proficiency.
Whether the national hieroglyphic system of the Hittites expressed the same Indo-European language as, according to Hrozny, their cuneiform does, we do not know, as further attempts to elucidate it made by Campbell Thompson 11 and Cowley," while in themselves very interesting experiments, do not seem to take us further than previous attempts by Sayce and others.
But the Peckhams' careful observations and experiments show that, with the American wasps, the victims stored in the nests are quite as often dead as alive; that those which are only paralysed live for a varying number of days, some more, some less; that wasp larvae thrive just as well on dead victims, sometimes dried up, sometimes undergoing decomposition, as on living and paralysed prey; that the nerve-centres are not stung with the supposed uniformity; and that in some cases paralysis, in others death, follows when the victims are stung in parts far removed from any nerve-centre.
Experiments made by Moore and Whitley at Port Erin in the Isle of Man show that the hydrogen-ion concentration falls from about 1084 in Dec. to about 108 ' 4 in April.
of all these experiments may be summed up in the statement that the amount of chemical action is proportional to the quantity of electricity which passes through the cell.
Taking the chemical equivalent weight of silver, as determined by chemical experiments, to be 107.92, the result described gives as the electrochemical equivalent of an ion of unit chemical equivalent the value 1 036 X 5.
Hittorf and many other observers have made experiments to determine the unequal dilution of a solution round the two electrodes when a current passes.
Hence experiments without separating diaphragms are to be preferred, and the apparatus may be considered effective when a consideraable bulk of intervening solution is left unaltered in composition.
The second relation, as we have seen, is not a strict consequence of theory, and experiments to examine it must be treated as an investigation of the limits within which solutions are dilute within the thermodynamic sense of the word, rather than as a test of the soundness of the theory.
It should be pointed out that no measurements on osmotic pressures or freezing points can do more than tell us that an excess of particles is present; such experiments can throw no light on the question whether or not those particles are electrically charged.
This is fully borne out by the experiments of Julius Thomsen, who found that the heat of neutralization of one gramme-molecule of a strong base by an equivalent quantity of a strong acid was nearly constant, and equal to 13,700 or 13,800 calories.
Many experiments have been made with a view of separating the two potential-differences which must exist in any cell made of two metals and a liquid, and of determining each one individually.
By experiments on diffusion this constant has been found by Scheffer, and the numbers observed agree with those calculated (HC1= 2.30, HNO 3 = 2 22, NaCI = I II).
Thus in 1857 he went to Peru in order to determine the magnetic equator; in1861-1862and 1864, he studied telluric absorption in the solar spectrum in Italy and Switzerland; in 1867 he carried out optical and magnetic experiments at the Azores; he successfully observed both transits of Venus, that of 1874 in Japan, that of 1882 at Oran in Algeria; and he took part in a long series of solar eclipse-expeditions, e.g.
He indulged in costly experiments in farming, so that in spite of the large income earned by his books he was not a rich man.
The nature of this element is a problem which has been provisionally, but not conclusively, solved by many psychologists; the method is necessarily experimental, and all experiments on feeling are peculiarly difficult.
Such experiments as these demonstrate the fundamental law that like poles repel each other; unlike poles attract.
For many experiments the field due to the earth's magnetism is sufficient; this is practically quite uniform throughout considerable spaces, but its total intensity is less than half a unit.
(36) From an analysis of a number of experiments made with rods of different dimensions H.
In the middle part of a rod which has a length of 400 or 500 diameters the effect of the ends is insensible; but for many experiments the condition of endlessness may be best secured by giving the metal the shape of a ring of uniform section, the magnetic field being produced by an electric current through a coil of wire evenly wound round the ring.
This operation, besides being very troublesome, was open to the objection that it was almost sure to produce a material but uncertain change in the physical constitution of the metal, so that, in fact, the results of experiments made before and after the treatment were not comparable.
We get therefore M 2 = MH X M/H = 27r 2 A(d 2 - l 2) 2 tan 0/t 2 d (42) s H 2 =Mhxh/M = 87r 2 Ad/tt 2 (d 2 -1 2) 2 tan B} (43) When a high degree of accuracy is required, the experiments and calculations are less simple, and various corrections are applied.
For experiments with long thin rods or wires it has an advantage over the other arrangements in that the position of the poles need not be known with great accuracy, a small upward or downward displacement having little effect upon the magnetometer deflection.
Since the induction B is equal to H 47rI, it is easy from the results of experiments such as that just described to deduce the relation between B and H; a curve indicating such relation is called a curve of induction.
For a series of experiments made with the same coil this fraction is constant, and we may write SB = kD.
The sample may have the form of a closed ring, upon which are wound the induction coil and another coil for taking the magnetizing current; or it may consist of a long straight rod or wire which can be slipped into a magnetizing coil such as is used in magnetometric experiments, the induction coil being wound upon the middle of the wire.
2 An interesting collection of W - B curves embodying the results of actual experiments by Ewing and Klaassen on different specimens of metal is given in fig.
2 Some experiments by F.
The experiments of K.
In many experiments, however, different inductions and frequencies are employed, and the hysteresis-loss is often expressed as ergs per cubic centimetre per cycle and sometimes as horse-power per ton.
The values assigned to H were calculated from H= 2ni/r, and ranged from 3.9 to 585, but inasmuch as no account was taken of any 2 Since in most practicable experiments H 2 is negligible in comparison with B 2, the force may be taken as B 2 /87r without sensible= error.
The greatest weight supported in the experiments was 14,600 grammes per square cm., and the corresponding induction 18, Soo units.
A part of one surface of the plate may be silvered, so that the polarized ray, after having once traversed the glass, is reflected back again; the rotation is thus doubled, and moreover, the arrangement is, for certain experiments, more convenient than the other.
In experiments on magnetic strains carried out by H.
In 1890 some experiments in which a coil was used were made by du Bois (Phil.
An account of their preliminary experiments by what they call the isthmus method was published in 1887 (Proc. Roy.
In most of the experiments the measurements were made by suddenly withdrawing the bobbin from its place ron FIG.
The highest induction reached in these experiments was 45,350 units, more than twice the value of any previously recorded.
The following table shows some results of other experiments in which H was believed to have sensibly the same value inside as outside the metal.
Some experiments made by H.
Ann., 1880, 11, 399) that in weak fields the relation of the magnetization I to the magnetizing force H is approximately expressed by an equation of the form I =aH +bH2, or K=I/H =a+bH, whence it appears that within the limits of Baur's experiments the magnetization curve is a parabola, and the susceptibility curve an inclined straight line, x being therefore a known function of H.
In some experiments carried out in 1887, Lord Rayleigh (Phil.
Experiments with annealed iron gave less satisfactory results, on account of the slowness with which the metal settled down into a new magnetic state, thus causing a " drift " of the magnetometer needle, which sometimes persisted for several seconds.
P. Joule, who in 1842 and 1847 described some experiments which he had made upon bars of iron and steel.
In 1885 it was shown by Bidwell, in the first of a series of papers on the subject, that if the magnetizing force is pushed beyond the point at which Joule discontinued his experiments, the extension of the bar does not remain unchanged, but becomes gradually less and less, until the bar, after first returning to its original length, ultimately becomes actually shorter than when in the unmagnetized condition.
In order to meet the objection that the phenomenon might be due to electromagnetic action between the coil and the rod, Bidwell made some experiments with iron rings, and found that the length of their diameters varied under magnetization in precisely the same manner as the length of a straight rod.
Experiments were afterwards made with rods of iron, nickel, and cobalt, the external field being carried up to the high value of 1500 units.
Certain experiments by C. G.
Some experiments were next undertaken with the view of ascertaining how far magnetic changes of length in iron were dependent upon the hardness of the metal, and the unexpected result was arrived at that softening produces the same effect as tensile stress; it depresses the elongation curve, diminishing the maximum extension, and reducing the " critical value " of the magnetizing force.
The experiments were not sufficiently numerous to indicate whether, as is possible, there is a critical degree of hardness for which the height of the elongation curve is a maximum.
Finally, experiments were made to ascertain the effect of ' The loads were successively applied in decreasing order of magnitude.
Most of the experiments described above have been repeated.
The same physicists have made some additional experiments upon the effect of tension on magnetic change of length.
Knott, who made an exhaustive series of experiments upon various metals in the form of tubes, concluded that in iron there was always a slight increase of volume, and in nickel and cobalt a slight decrease.
regarded as a " correction " to be applied to the results of experiments on magnetic change of length, the magnetic stress being no less an extraneous effect than a stress applied mechanically.
The results of their experiments embrace a multiplicity of details of which it is impossible to give an adequate summary.
The following table shows the values of I and H corresponding to the Villari critical point in some of Ewing's experiments: The effects of pulling stress may be observed either when the wire is stretched by a constant load while the magnetizing force is varied, or when the magnetizing force is kept constant while the load is varied.
In the latter case the first application of stress is always attended by an increase-often a very great one-of the magnetization, whether the field is weak or strong, but after a load has been put on and taken off several times the changes of magnetization become cyclic. From experiments of both classes it appears that for a given field there is a certain value of the load for which the magnetization is a maximum, the maximum occuring at a smaller load the stronger the field.
Some experiments by A.
4 Chree's experiments were undertaken at the suggestion of J.
Ewing's independent experiments showed that the magnetization curve for a cobalt rod under a load of 16.2 kilogrammes per square mm.
Mag., 1898, 46, 261) have investigated the effects of hydrostatic pressure upon magnetization, using the same pieces of iron and nickel as were employed in their experiments upon magnetic change of volume.
Experiments on the effect of external hydrostatic pressure upon the magnetization of iron rings have also been made by F.
The first exact experiments demonstrating the changes which occur in the permeability of iron,, 3 Phil.
The following are the chief results of Hopkinson's experiments: For small magnetizing forces the magnetization of iron steadily increases with rise of temperature till the critical temperature is approached, when the rate of increase becomes very high, the permeability in some cases attaining a value of about i i,000; the magnetization then with remarkable suddenness almost entirely disappears, the permeability falling to about 1.14.
For strong magnetizing forces (which in these experiments did not exceed II= 48.9) the permeability remains almost constant at its initial value (about 400), until the temperature is within nearly i oo of the critical point; then the permeability diminishes more and more rapidly until the critical point is reached and the magnetization vanishes.
As in Hopkinson's experiments, ring magnets were employed; these were wound with primary and secondary coils of insulated platinum wire, which would bear a much higher temperature than copper without oxidation or fusion.
Some preliminary experiments showed the striking difference in the effects of annealing at a red heat (840° C.) and at a low white heat (1'50° C.).
Experiments were made at several constant temperatures with varying magnetic fields, and also at constant fields with rising and falling temperatures.
Experiments on the effect of high temperatures have also been made by M.
Most of the permeability-temperature curves were more or less convex towards the axis of temperature, and in all the experiments except those with annealed iron and steel wire, the permeability was greatest at the lowest temperature.
Experiments with the sample of unannealed iron failed to give satisfactory results, owing to the fact that no constant magnetic condition could be obtained.
Honda and Shimizu have made similar experiments at the temperature of liquid air, employing a much wider range of magnetizing forces (up to about 700 C.G.S.) and testing a greater variety of metals.
Other experiments relating to the effect of temperature upon permanent magnets have been carried out by J.
Experiments on the subject have also been made by E.
Hadfield 7 have made very careful experiments on an alloy containing 22.42% of manganese, 11.65% of ' J.
4 No record can be found of experiments with manganese at the temperature of liquid air or hydrogen; probably, however, negative results would not be published.
Among the most important experiments on the influence of magnetic force at different temperatures are those of J.
Other experiments showed the relation of resistance to temperature (from o° to about 90°) in different constant fields.
The results of experiments as to the effect of magnetization were for long discordant and inconclusive, sufficient care not having been taken to avoid sources of error, while the effects of hysteresis were altogether disregarded.
Important experiments on the susceptibility of oxygen at different pressures and temperatures were carried out by P. Curie (C.R.
In the first experiments it was calculated from observations of the mutual induction of two conducting circuits in air and in the liquid; the results for oxygen at-182° C. were I 00287, 228 X IO-6.
The susceptibility of air being known - practically it was negligible in these experiments - that of liquid oxygen can at once be found.
The mean of 36 experiments with 7 balls gave = 1 .
- Experiments by J.
Some experiments by F.
In one case the hysteresis loss per cubic centimetre per cycle was 16,100 ergs for B =1 5,900, and only 1200 ergs for B = 20,200, the highest induction obtained in the experiment; possibly it would have vanished before B had reached 21,000.2 These experiments prove that actual friction must be almost entirely absent, and, as Baily remarks, the agreement of the results with the previously suggested deduction affords a strong verification of Ewing's form of the molecular theory.
The greatest of Gilbert's discoveries was that the globe of the earth was magnetic and a magnet; the evidence by which he supported this view was derived chiefly from ingenious experiments made with a spherical lodestone or lerrella, as he termed it, and from his original observation that an iron bar could be magnetized by the earth's force.
He also carried out some new experiments on the effects of heat, and of screening by magnetic substances, and investigated the influence of shape upon the magnetization of iron.
Coulomb, 2 however, by using long and thin steel rods, symmetrically magnetized, and so arranged that disturbing influences became negligibly small, was enabled to deduce from his experiments with reasonable certainty the law that the force of attraction or repulsion between two poles varies inversely as the square of the distance between them.
Rowland,' whose careful experiments led to general recognition of the fact previously ignored by nearly all investigators, that magnetic susceptibility and permeability are by no means constants (at least in the case of the ferromagnetic metals) but functions of the magnetizing force.
The artificial preparation of minerals, especially of apatite and isomorphous minerals and of crystalline oxides, was another subject in which he made many experiments.
This discharge, which is identical with the " brush " discharge of laboratory experiments, usually appears as a tip of light on the extremities of pointed objects such as church towers, the masts of ships, or even the fingers of the outstretched hand: it is commonly accompanied by a crackling or fizzing noise.
On his farm Smith carried out his experiments in deep and thorough draining, and also invented a reaping machine, the subsoil plough and numerous other valuable appliances.
After the coup d'etat of 1851 he settled with his family in Jersey, where he pursued agricultural experiments and wrote his socialist poem La Greve de Samarez.
Lambert's most important work, Pyrometrie (Berlin, 1779), is a systematic treatise on heat, containing the records and full discussion of many of his own experiments.
Lavoisier he made an important series of experiments on specific heat (1782-1784), in the course of which the "ice calorimeter" was invented; and they contributed jointly to the Memoirs of the Academy (1781) a paper on the development of electricity by evaporation.
It is a region of lakes and morasses, of arid plains and high temperatures, but experiments with irrigation toward the end of the 19th century were highly successful and considerable tracts have since been brought under cultivation.
Mendel made his chief experiments with cultivated varieties of the self-fertilizing edible pea.
In each set of experiments he concentrated his attention on the one character selected for observation.
The one fact which the Lamarckians can produce in their favour is the account of experiments by Brown-Sequard, in which he produced epilepsy in guinea-pigs by section of the large nerves or spinal cord, and in the course of which he was led to believe that in a few rare instances the artificially produced epilepsy and mutilation of the nerves was transmitted.
On the other hand, the vast number of experiments in the cropping of the tails and ears of domestic animals, as well as of similar operations on man, are attended with negative results.
In such experiments the narrowness of the zones renders necessary a pretty close approximation to the geometrical conditions.
In his experiments upon this subject Fraunhofer employed plates of glass dusted over with lycopodium, or studded with small metallic disks of uniform size; and he found that the diameters of the rings were proportional to the length of the waves and inversely as the diameter of the disks.
- The phenomena to be considered under this head are of less importance than those investigated by Fraunhofer, and will be treated in less detail; but in view of their historical interest and of the ease with which many of the experiments may be tried, some account of their theory cannot be omitted.
Descartes strengthened these views, both by experiments and geometrical investigations, in his Meteors (Leiden, 1637).
The subsequent experiments of Snellen, Senftleben, and, more lately, of Turner, seem to show that if the eyeball be protected from the impingement of foreign particles, an accident to which it is liable owing to its state of anaesthesia, the ulceration may be warded off indefinitely.
From these experiments it is shown that cells taken from these growths and introduced into animals of the same species give rise to a cancerous growth, whose cells have acquired unlimited powers of proliferation.
A number of interesting experiments, designed to test the relationship between the condition of suppuration and the production of amyloid, have been made of late years.
Welch produced oedema of the lungs experimentally by increasing the pressure in the pulmonary vessels by ligature of the aorta and its branches, but this raised the blood pressure only about one-tenth of an atmosphere, while in some of Loeb's experiments the osmotic pressure, due to retained metabolic products, was equal to over thirty atmospheres.
The most interesting of all the experiments, not alone from its own history, but also from the fact that it attracted the support of many of the most intellectual and cultured Americans was that of Brook Farm.
His works contain, however, many original experiments, and excellent practical observations.
Moreover, Haller's views did not rest on a priori speculation, but on numerous experiments.
He spent about three months in the Low Countries, and in March 1737 returned to Cirey, and continued writing, making experiments in physics (he had at this time a large laboratory), and busying himself with iron-founding, the chief industry of the district.
In Parthey's edition (Berlin, 1850) other recipes for the manufacture of kuphi, by Galen and Dioscorides, are given; also some results of the editor's own experiments.
In acoustics he invented, about 1819, the improved siren which is known by his name, using it for ascertaining the number of vibrations corresponding to a sound of any particular pitch, and he also made experiments on the mechanism of voice-production.
Experiments on a short section of the line were made in 1900, and later schemes were set on foot to electrify the District system and bring under one general control this railway, other lines in deep level " tubes " between Baker Street and Waterloo, between Charing Cross, Euston and Hampstead, and between Hammersmith, Brompton, Piccadilly, King's Cross and Finsbury Park, and the London United Tramways Company.
The Metropolitan Board of Works, and the commissioners of sewers in the City, began experiments with electric light.
Experiments have also been made with the Kachin hillmen and with the Shans; but the Burmese character is so averse to discipline and control in petty matters that it is impossible to get really suitable men to enlist even in the civil police.
Schott's experiments at the Jena glass-works.
Harcourt began experiments in glass-making, in which he was subsequently joined by G.
Experiments were also tried with a violet-coloured glass, a violet opal, a transparent black and with glasses shading from red to blue, red to amber and blue to green.
The temperature required in the fusion of sheet-glass and of other glasses produced in tank furnaces is much lower than that attained in steel furnaces, and it is consequently pos Since the discovery of the Rntgen rays, experiments have been made to ascertain the effects of the different constituents of glass on the transparency of glass to X-rays.
Edward Dillon (Glass, 1902) has very properly laid stress on the importance of the enamelled Saracenic glass of the r3th, 14th and r 5th centuries, pointing out that, whereas the Romans and Byzantine Greeks made some crude and ineffectual experiments in enamelling, it was under Saracenic influence that the processes of enamelling and gilding on glass vessels were perfected.
The famous experiments of H.
Parallel experiments with layers of dough or sand plus some connecting material proved that the particles in all cases moved along the same tracks as would be followed by a flowing cylinder of liquid.
This theorem was published in 1643, at the end of his treatise De motu gravium projectorum, and it was confirmed by the experiments of Raffaello Magiotti on the quantities of water discharged from different ajutages under different pressures (1648).
In the hands of Blaise Pascal (1623-1662) hydrostatics assumed the dignity of a science, and in a treatise on the equilibrium of liquids (Sur l'equilibre des liqueurs), found among his manuscripts after his death and published in 1663, the laws of the equilibrium of liquids were demonstrated in the most simple manner, and amply confirmed by experiments.
The theorem of Torricelli was employed by many succeeding writers, but particularly by Edme Mariotte (1620-1684), whose Traite du mouvement des eaux, published after his death in the year 1686, is founded on a great variety of well-conducted experiments on the motion of fluids, performed at Versailles and Chantilly.
Following in the steps of the Abbe Charles Bossut (Nouvelles Experiences sur la resistance des fluides, 1777), he published, in 1786, a revised edition of his Principes d'hydraulique, which contains a satisfactory theory of the motion of fluids, founded solely upon experiments.
The theory contained in that edition was founded on the experiments of others, but he soon saw that a theory so new, and leading to results so different from the ordinary theory, should be founded on new experiments more direct than the former, and he was employed in the performance of these from 1780 to 1783.
The experiments of Bossut were made only on pipes of a moderate declivity, but Dubuat used declivities of every kind, and made his experiments upon channels of various sizes.
From a collection of the best experiments by previous workers he selected eighty-two (fifty-one on the velocity of water in conduit pipes, and thirty-one on its velocity in open canals); and, discussing these on physical and mechanical principles, he succeeded in drawing up general formulae, which afforded a simple expression for the velocity of running water.
P. Hachette (1769-1834) in1816-1817published memoirs containing the results of experiments on the spouting of fluids and the discharge of vessels.
Extensive experiments on the discharge of water from orifices (Experiences hydrauliques, Paris, 1832) were conducted under the direction of the French government by J.
P. P. Boileau (1811-1891) discussed their results and added experiments of his own (Traite de la mesure des eaux courantes, Paris, 1854).
The experiments of J.
Francis (Lowell Hydraulic Experiments, Boston, Mass., 1855) led him to propose variations in the accepted formulae for the discharge over weirs, and a generation later a very complete investigation of this subject was carried out by H.
C. Cunningham's experiments on the Ganges canal.
Indeed, experiments have been made in this direction near Cardiff in South Wales.
Experiments have shown that excellent effects can be obtained by applying 5 or 6 cwt.
Experiments show that pure cultures, when mixed with garden soil constantly moistened short of saturation and kept in the dark at a temperature of 14° C., will retain their vitality for more than ten months; from moist soil kept at 26° C. they die out in about two months; from moist soil at 30° C. in seventeen days; and in dry soil at the same temperature within a week.
In 1886 experiments were conducted, under certain restrictions, and the plant was grown in Norfolk, Kent and other counties with sufficient success to prove the entire practicability of raising tobacco as a commercial crop in England.
His father, a drysalter and dealer in colours, used sometimes to make experiments in the hope of finding improved processes for the production of his wares, and thus his son early acquired familiarity with practical chemistry.
On this theory he prepared artificial manures containing the essential mineral substances together with a small quantity of ammoniacal salts, because he held that the air does not supply ammonia fast enough in certain cases, and carried out systematic experiments on ten acres of poor sandy land which he obtained from thr town of Giessen in 1845.
But in practice the results were not wholly satisfactory, and it was a long time before he recognized one important reason for the failure in the fact that to prevent the alkalis from being washed away by the rain he had taken pains to add them in an insoluble form, whereas, as was ultimately suggested to him by experiments performed by J.
His experiments convinced him of the practicability of an electric submarine cable connexion between Ireland and America; and having in 1855 already discussed the question with Cyrus Field, who with J.
Among the earliest experiments in this branch of the subject were those of Sir H.
The furnace used by Henri Moissan in his experiments on reactions at high temperatures, on the fusion and volatilization of refractory materials, and on the formation of carbides, suicides and borides of various metals, consisted, in its simplest form, of two superposed blocks of lime or of limestone with a central cavity cut in the lower block, and with a corresponding but much shallower inverted cavity in the upper block, which thus formed the lid of the furnace.
In 1846 he began experiments on the temperature of the earth at different depths and in different soils near Edinburgh, which yielded determinations of the thermal conductivity of trap-tufa, sandstone and pure loose sand.
At the Oxford botanic garden he conducted numerous experiments upon the effect of changes in soil, light and the composition of the atmosphere upon vegetation.
On the strength of similar arrangements of lenses and mirrors the invention of the camera obscura has also been claimed for Leonard Digges, the author of Pantometria (1571), who is said to have constructed a telescope from information given in a book of Bacon's experiments.
He also made great use of the simple dark chamber for his optical experiments with prisms, &c. Joseph Priestley (1772) mentions the application of the solar microscope, both to the small and portable and the large camera obscura.
His experiments with Sir Humphrey Davy in endeavouring to fix the images of natural objects as seen in the camera were published in 1802 (Journ.
Experiments in steam navigation were carried out in 1802 with the "Charlotte Dundas" on the Forth and Clyde Canal at Grangemouth.
Hales's Philosophical Experiments, published in 1739.
Experiments on monkeys have, however, given negative results.
This hypothesis he verified quantitatively by experiments, performed at the end of 1761.
Stuhlmann's experiments with G.
The first volume, Vegetable Staticks (1727), contains an account of numerous experiments in plant-physiology - the loss of water in plants by evaporation, the rate of growth of shoots and leaves, variations in root-force at different times of the day, &c. Considering it very probable that plants draw "through their leaves some part of their nourishment from the air," he undertook experiments to show in "how great a proportion air is wrought into the composition of animal, vegetable and mineral substances"; though this "analysis of the air" did not lead him to any very clear ideas about the composition of the atmosphere, in the course of his inquiries he collected gases over water in vessels separate from those in which they were generated, and thus used what was to all intents and purposes a "pneumatic trough."
The second volume (1733) on Haemostaticks, containing experiments on the "force of the blood" in various animals, its rate of flow, the capacity of the different vessels, &c., entitles him to be regarded as one of the originators of experimental physiology.
The outcome was of importance far beyond the narrow limits of the duchy; for all Germany watched the constitutional experiments of the southern states.
The other volumes dealt with (a) iron and steel, (b) copper and brass, their smelting, conversion and assaying, and chemical experiments thereon.
Nor is this its only association with science; for it was one of the spots chosen by Sir Edward Sabine for his series of pendulum experiments in 1823.
To enable these conditions to be fulfilled, as well as to ensure that the machine, when it fell, should fall on water, the experiments were carried out on the Potomac river, some 30 m.
After experiments in the Zeiss works, the erecting of Porro's prisms simultaneously permitted a convenient adaptation to the eye-distance of the observer.
If the alloy were a true chemical compound the counteracting electromotive force should not occur; experiments in this direction are much needed.
P. Laurie has determined the electromotive force of a series of copper-zinc, copper-tin and gold-tin alloys, and as the result of his experiments he points to the existence of definite compounds.
Their experiments, although not conclusive, appear to indicate that the molecule of a metal when in dilute solution often consists of one atom.
The reader possessed of no previous knowledge of electrical phenomena will best appreciate the meaning of the terms employed by the aid of a few simple experiments.
Soc., 1880, 30, p. 411, showing experiments on residual charge of condensers and a comparison between the behaviour of dielectrics and glass fibres under torsion.
By his practical experiments and by his writings he gained a considerable reputation as an economist; but his ambition was not content with this, and he sought to extend his influence by joining first the Freemasons and afterwards (1779) the Rosicrucians.
Clausius (1850), applying the same assumption, deduced the same value of F'(t), and showed that it was consistent with the mechanical theory and Joule's experiments, but required that a vapour like steam should deviate more considerably from the gaseous laws than was at that time generally admitted.
Joule's experiments on the equivalence of W and H were not sufficiently precise to decide the question.
If we also assume that they are constant with respect to temperature (which does not necessarily follow from the characteristic equation, but is generally assumed, and appears from Regnault's experiments to be approximately the case for simple gases), the expressions for the change of energy or total heat from 00 to 0 may be written E - Eo = s(0 - 0 0), F - Fo = S(0-00).
- William Thomson (Lord Kelvin), who wars the first to realize the importance of the absolute scale in thermodynamics, and the inadequacy of the test afforded by Boyle's law or by experiments on the constancy of the specific heat of gases, devised a more delicate and practical test, which he carried out successfully in conjunction with Joule.
As the result of their experiments on actual gases (air, hydrogen, and C02), Joule and Thomson (Phil.
By experiments at different temperatures between o° and 00° C., they found that the cooling effect per atmosphere of pressure varied inversely as the square of the absolute temperature for air and CO 2.
Soc. Ed., 1854) to represent Regnault's experiments on the deviations of CO 2 from.
Experiments by Natanson on CO 2 at 17° C. confirm those of Joule and Thomson, but show a slight increase of the ratio do/dp at higher pressures, which is otherwise rendered probable by the form of the isothermals as determined by Andrews and Amagat.
More recent experiments by J.
The introduction of the covolume, b, into the equation is required in order to enable it to represent the behaviour of hydrogen and other gases at high temperatures and pressures according to the experiments of Amagat.
The value of the co-aggregation volume, c, at any temperature, assuming equation (17), may be found by observing the deviations from Boyle's law and by experiments on the Joule-Thomson effect.
(18) Experiments at two temperatures suffice to determine both c and n if we assume that b is equal to the volume of the liquid.
This fact was not observed (that is, the collections of examples were not made) till recently, when experiments in private non-spiritualist circles drew attention to crystal-gazing, a practice always popular among peasants, and known historically to have survived through classical and medieval times, and, as in the famous case of Dr Dee, after the Reformation.
In experiments with magnifying glasses, and through spars, the ordinary effects of magnifying and of alteration of view are sometimes produced; sometimes they are not.
The evidence, of course, is necessarily only that of the scryers themselves, but repeated experiments by persons of probity, and unfamiliar with the topic, combined with the world-wide existence of the practice, prove that hallucinatory pictures are really induced.
It is useless to make experiments with hysterical and visionary people, "whose word no man relies on"; they may have the hallucinatory experiences, but they would say that they had in any case.
1 A number of examples occurring during experiments made by the present writer and by his acquaintances in 1897 were carefully recorded and attested by the signatures of all concerned.
The experiments took this form: any person might ask the scryer (a lady who had never previously heard of crystal-gazing) "to see what he was thinking of."
Whoever can believe that the successes were numerous and that descriptions were given correctly - not only of facts present to the minds of inquirers, and of other persons present who were not consciously taking a share in the experiments, but also of facts necessarily unknown to all concerned - must of course be most impressed by the latter kind of success.
The writer is acquainted with no experiments in which it was attempted to discern the future (except in trivial cases as to events on the turf, when chance coincidence might explain the successes), and only with two or three cases in which there was an attempt to help historical science and discern the past by aid of psychical methods.
The results were interesting and difficult to explain, but the experiments were few.
The writer has no experience of trance, sleep or auto-hypnotization produced in such experiments; scryers have always seemed to retain their full normal consciousness.
The history of crystal-gazing is here traced, and many examples of the author's own experiments are recorded.
v., contains anthropological examples and a series of experiments.
These Egyptian experiments of 1830 were vitiated by their method, the scryer being asked to see and describe a given person, named.
Experiments on this point were made by Anossow in 1835, but they have never been followed in practice.
Some of his experiments on this subject were performed before Pierre Louis M.
Such slipping had shown itself at high exhaustions in the experiments of A.
Experiments made by a person who possesses a good memory seem to show that the thing is very possible, especially if Darnley revised Crawford's notes.
9) on the latter is carefully counted, and the experiments repeated at different temperatures.
and Winnecke, the last-named making the necessary experiments at Carlsruhe.
Angelo Secchi (Comptes rendus, xli., 18 55, p. 906) gives an account of some experiments with a similar micrometer; and Ignarjio Porro (Comptes rendus, xli.
Grain, wine, oil and fruit are produced in the district, and there is a municipal farm, founded in 1885, for experiments in viticulture.
Polar explorers making sections across the great expanses of water with everfrequently repeated those experiments in deep-sea soundings, increasing accuracy, and in that work the government surveying both William Scoresby and Sir John Ross obtaining notable ships have also been engaged, vast stretches of the Indian and results, though not reaching depths of more than 1200 fathoms. Pacific Oceans having been opened up to knowledge by H.M.SS.
Their experiments show that in similar conditions the evaporation of sea-water amounts to from 70 to 91% of the evaporation of fresh water, a fact of some importance in geophysics on account of the vast expanses of ocean the evaporation from which determines the rainfall and to a large extent the heat-transference in the atmosphere.
Sarasin and longer series of experiments by Tornde and Kriimmel this relation is shown to be so close that the salinity of a sample can be ascertained by determining the index of refraction.
Many experiments have also been made by the use of photographic plates in order to find the greatest depth to which light penetrates.
When a quantity of a fine white powder is thrown in, the light reflected by the white particles as they sink assumes an intense blue colour, and the experiments of J.
Buchanan found a mean of 20 experiments made by piezometers sunk in great depths on board the " Challenger " give a coefficient of compressibility K=491 X 107; but six of these experiments made at depths of from 2740 to 3125 fathoms gave K=480Xio 7.
Experiments have also been made with a device in which the air-supply is obtained by the evaporation of liquid air absorbed in asbestos.
It can be condensed into the liquid state by cold or by pressure, and experiments by G.
Continuing these experiments, they found that in acetylene gas under ordinary pressures the decomposition brought about in one portion of the gas, either by heat or the firing in it of a small detonator, did not spread far beyond the point at which the decomposition started, while if the acetylene was compressed to a pressure of more than 30 lb on the square inch, the decomposition travelled throughout the mass and became in reality detonation.
Very extensive experiments, however, made by Drs N.
In experiments with these various bodies it is found that they are all of them effective in also ridding the acetylene of the ammonia and sulphuretted hydrogen, provided only that the surface area presented to the gas is sufficiently large.
For longer experiments he used a " Compteur " or mechanical integrator, suggested by J.
As a single instance of this may be mentioned some experiments of Lord Rayleigh (Proc. Roy.
(If the molecules of air at normal temperature and pressure were arranged in cubical order, the edge of each cube would be about 2.9 X I o - ' cms.; the average diameter of a molecule in air is 2.8X Io - 8 cms.) Further and very important evidence as to the nature of the gaseous state of matter is provided by the experiments of Joule and Kelvin.
These experiments showed that the change in the temperature of a gas, consequent on its being allowed to stream out into a vacuum, is in general very slight.
Franklin sailed again for America in August 1762, hoping to be able to settle down in quiet and devote the remainder of his life to experiments in physics.
In navigation he suggested many new contrivances, such as water-tight compartments, floating anchors to lay a ship to in a storm, and dishes that would not upset during a gale; and beginning in 1757 made repeated experiments with oil on stormy waters.
He took a prominent part in aeronautic experiments during his stay in France.
Experiments and Observations on Electricity (London, 1769) was translated into French by Barbeu Dubourg (Paris, 1773); Vaughan attempted a more complete edition, Political, Miscellaneous and Philosophical Pieces (London, 1 779); an edition in three volumes appeared after Franklin's death (London, 1806); what seemed the authentic Works, as it was under the care of Temple Franklin, was published at London (6 vols., 1817-1819; 3 vols., 1818) and with some additional matter at Philadelphia (6 vols., 1818).
In 1853 exhaustive experiments were carried out in England with a view to ascertaining whether it would be possible so to treat alcohol as to allow it to be used industrially without, at the same time, any risk of the revenue being defrauded.
These experiments resulted in the legislation of 1855, when the use of duty-free alcohol mixed with 10% by volume of wood naphtha, known as methylated spirits, was authorized for manufacturing purposes only.
The school was denounced in the press, was not pecuniarily successful, and in 1839 was given up, although Alcott had won the affection of his pupils, and his educational experiments had challenged the attention of students of pedagogy.
His Sonnets and Canzonets (1882) are chiefly interesting as an old man's experiments in verse.
Many experiments have been made with a view to determining the difference in chemical constitution of marcasite and pyrites, but with no very definite results.
His experiments, in the same year, on the photographic registration of stellar spectra, marked an innovation of a momentous character.
In solar physics Huggins suggested a spectroscopic method for viewing the red prominences in daylight; and his experiments went far towards settling a much-disputed question regarding the solar distribution of calcium.
About 1885 he took up the laboriously scientific method of the pointillists, but after a few years of these experiments he returned to a broader and more attractive manner.
Many interesting experiments in settling lands have been tried.
Ballance at once raised the pay of members from £150 to £240 a year, but otherwise directed his energies to constitutional reforms and social experiments.
On recent social and political changes and experiments there are: W.
P. Reeves, State Experiments in Australia and New Zealand (2 vols., London, 1902); H.
Having at his disposal a band of picked virtuosi he could produce effects as different from the tentative experiments of C. P. E.
Experiments, which will be described most conveniently when we discuss methods of determining the frequencies of sources, prove conclusively that for a given note the frequency is the same whatever the source of that note, and that the ratio of the frequencies of two notes forming a given musical interval is the same in whatever part of the musical range the two notes are situated.
Experiments, referred to later, have been made to find the amplituae of swing of the air particles in organ pipes.
Thus Regnault in his classical experiments (described below) found that the velocity of the report of a pistol carried through a pipe diminished with the intensity, and his results have been confirmed by J.
In 1822 a commission of the Bureau des Longitudes made a series of experiments between Montlhery and Villejuif, I r m.
In a long series of experiments carried out by V.
A short account of these experiments is given in Phil.
On page 459 of the Memoire will be found a list of previous careful experiments on the velocity of sound.
In the open-air experiments the receiver consisted of a large see below.
In some experiments in which contact was made instead of broken, Regnault determined the personal equation of the apparatus.
1280 metres arid 2445 metres, obtaining from the first U 0 =331.37 met./sec.; but the number of experiments over the longer distance was greater, and he appears to have put more confidence in the result from them, viz.
It is obvious from the various experiments that the velocity of sound in dry air at o° C. is not yet known with very great accuracy.
Violle and Vautier made some later experiments on the propagation of musical sounds in a tunnel 3 metres in diameter (Ann.
Experiments on the velocity of sound in iron have been made on lengths of iron piping by J.
The experiments were not satisfactory, and it is sufficient to say that the results accorded roughly with the value given by theory.
Experiments may be made with plane and curved mirrors to verify these laws, but it is necessary to use short waves, in order to diminish diffraction effects.
All experiments in frequency show that two notes, forming a definite musical interval, have their frequencies always in the same ratio wherever in the musical scale the two notes are situated.
Experiments have been made on this subject by various workers, the most extensive by W.
It may, however, be stated here that certain experiments of Helmholtz appear to show that the epoch of the harmonics has not much effect on the quality.
The first may be illustrated by Lord Rayleigh's experiments to determine the amplitude of vibration in waves only just audible (Sound, ii.
In a later series of experiments Lord Rayleigh (Phil.
The second method may be illustrated by the experiments of M.
From subsidiary experiments (for which the original memoir must be consulted) the pressure variations within the resonator could be calculated from the movements of the plate.
In a later series of experiments (Science Abst.
Experiments on the velocity in pipes were carried out by H.
§ 7 seq.) describes a number of beautiful experiments with jets at higher pressure than ordinary, say to in.
Koenig, Quelques experiences d'acoustique (1882) describes apparatus and experiments, intended to show, in opposition to Helmholtz, that beats coalesce into tones, and also that the quality of a note is affected by alteration of phase of one of its component overtones relative to the phase of the fundamental.
John Tyndall, Sound (5th ed., 1893), originally delivered as lectures, treats the subject descriptively, and is illustrated by a large number of excellent experiments.
(1843-1855), while the influence of his discussions doubtless led to or gave encouragement to other socialistic experiments, such as that at Brook Farm.
An important series of experiments on the strength of masonry, brick and concrete structures will be found in the Zeitschr.
The experiments of Sir B.
Baker then described the results of experiments on repetition of stress, and added that " hundreds of existing bridges which carry twenty trains a day with perfect safety would break down quickly under twenty trains an hour.
The experiments of A.
Bridge sections designed by this rule differ little from those designed by formulae based directly on Wohler's experiments.
Wohler's and Bauschinger's experiments give values of t, u, and s, for some materials.
His experiments greatly interested Benjamin Franklin, who used to visit him and Goethe always regarded his rejection by the academy as a glaring instance of scientific despotism.
He mentions two experiments made by him to prove this - one by cutting off the staminal flowers in Maize, and the other by rearing the female plant of Mercurialis apart from the male.
In his Statical Essays (1727) he gave an account of numerous experiments and observations which he had made on the nutrition of plants and the movement of sap in them.
Darwin's experiments in reference to the movements of climbing and twining plants, and of leaves in insectivorous plants, have opened up a wide field of inquiry as to the relation between plants and the various external factors, which has attracted numerous workers.
As will be seen later, modern experiments have confirmed the entire absence of any effect, such as convection would produce, to very high precision.
The corollary, that the electric resistance of a metal can be determined in absolute units by experiments on the reflexion of heat-rays from its surface, is a striking illustration of the unification of the various branches of physical science, which has come in the train of the development of the theory of the aether.
The experiments of C. J.
In this attempt he was unsuccessful, but the observations he made in the course of his experiments induced him, early in 1856, to try the effect of treating aniline sulphate with bichromate of potash.
An account of the work he did with this instrument was published in 1660 under the title New Experiments PhysicoMechanical touching the spring of air and its effects.
Yet he would not avow himself a follower of Bacon or indeed of any other teacher: on several occasions he mentions that in order to keep his judgment as unprepossessed as' might be with any of the modern theories of philosophy, till he was "provided of experiments" to help him judge of them, he refrained from any study of the Atomical and the Cartesian systems, and even of the Novum Organum itself, though he admits to "transiently consulting" them about a few particulars.
He himself was an alchemist; and believing the transmutation of metals to be a possibility, he carried out experiments in the hope of effecting it; and he was instrumental in obtaining the repeal, in 1689, of the statute of Henry IV.
His first book on the subject was The Sceptical Chemist, published in 1661, in which he criticized the "experiments whereby vulgar Spagyrists are wont to endeavour to evince their Salt, Sulphur and Mercury to be the true Principles of Things."
He also studied the chemistry of combustion and of respiration, and made experiments in physiology, where, however, he was hampered by the "tenderness of his nature" which kept him from anatomical dissections, especially of living animals, though he knew them to be "most instructing."