Delambre gives 3 the following comparison between the results of Gascoigne's measurements of the sun's semi-diameter and the computed results from modern determinations: Gascoigne.
His determinations of pitch by a weighted wire are not trustworthy; Ellis thinks they are not safe within four or five vibrations per second, but gives a mean pitch for this organ, when altered, of a' 395.2.
Before the end of 1906 fifty-two separate trades in Victoria had obtained special boards, by whose determinations their operations were controlled.
Recent determinations by H.
The cadmium molecule, as shown by determinations of the density of its vapour, is monatomic. The metal unites with the majority of the heavy metals to form alloys; some of these, the so-called fusible alloys, find a useful application from the fact that they possess a low melting-point.
Soc., 1905, 27, p. 222), by determinations of the ratio of cadmium chloride to silver chloride, and of the amount of silver required to precipitate cadmium chloride.
The molecular weight determinations of W.
The superior accuracy of his determinations was attested by S.
In fact, the means of the best determinations of each of these quantities separately agree with one another more closely than do the various values of either.
To him belongs the merit of carrying out some of the earliest determinations of the quantities by weight in which acids saturate bases and bases acids, and of arriving at the conception that those amounts of different bases which can saturate the same quantity of a particular acid are equivalent to each other.
South and west the bounding territories are well fixed in geographical position by the Indian survey determinations of the value of Himalayan peaks.
Among his chief systematic determinations we may mention that he refers the tinamous to the rails, because apparently of their deep " notches," but otherwise takes a view of that group more correct according to modern notions than did most of his contemporaries.
Even prior to the discovery of petroleum in commercial quantities, a number of chemists had made determinations of the chemical composition of several different varieties, and these investigations, supplemented by those of a later date, show that petroleum consists of about 84% by weight of carbon with 12% of hydrogen, and varying proportions of sulphur, nitrogen and oxygen.
In all the cases which have yet arisen in astronomy the extraneous forces are so small compared with the gravitation of the central body that the orbit is approximately an ellipse, and the preliminary computations, as well as all determinations in which a high degree of precision is not necessary, are made on the hypothesis of elliptic orbits.
According to the law of Avogadro, equal volumes of different gases under the same conditions of temperature and pressure contain equal numbers of molecules; therefore, since the density depends upon the number of molecules present in unit volume, it follows that for a comparison of the densities of gases, the determinations must be made under coincident conditions, or the observations reduced or re-computed for coincident conditions.
Stadel's determinations: CH 3 CC1 3..
Hence within narrow limits Kopp's determinations were carried out under coincident conditions, and therefore any regularities presented by the critical volumes should be revealed in the specific volumes at the boiling-point.
From Reicher's determinations, the exact transition point is 95.6°; it rises with increasing pressure about 0.05° for one atmosphere; the density of the rhombic form is greater than that of the monoclinic. The equilibria of these modifications may be readily represented on a pressure-temperature diagram.
No absolutely accurate determinations appear to have been made recently.
Numerous determinations of the atomic weight of nitrogen have been made by different observers, the values obtained varying somewhat according to the methods used.
These methods have been purely chemical (either gravimetric or volumetric), physical (determinations of the density of nitrogen, nitric oxide, &c.) or physicochemical.
A very large amount of local detailed observation in the various sea-areas must be the next important work to be undertaken: this means currentobservations b y direct readings of metres, by the employment of drift-bottles and numerous determinations of temperature and salinity at all seasons.
The mean result of the best determinations shows that when a current of one ampere is passed for one second, a mass of silver is deposited equal to o ooi i 18 gramme.
Determinations have been made with calcium oxalate, CaC 2 04+H 2 0, which is easily decomposed by acids, oxalic acid and a soluble calcium salt being formed.
Dark coloured micas are strongly pleochroic. Accurate determinations of the optical orientation, as well as the symmetry of the etching figures on the cleavage planes, seem to suggest that the micas, except muscovite, may be anorthic rather than monoclinic in crystallization.
The most careful determinations are affected by systematic errors arising from those diurnal and annual changes of temperature, the effect of which cannot be wholly eliminated in astronomical observation; and the recently discovered variation of latitude has introduced a new element of uncertainty into the determination.
This last value agrees very closely with a determination made by Gill at the Cape of Good Hope, and most other recent determinations give values exceeding 20.50".
The distribution of magnetism and the position of the poles in magnets of other shapes, such as cylindrical or rectangular bars, cannot be specified by any general statement, though approximate determinations may be obtained experimentally in individual cases.'
The standard induction in reference to determinations of hysteresis is generally taken as 2500, while the loss is expressed in watts per lb at a frequency of ioo double reversals, or cycles, per second.
- The following are recent determinations of the magnetic susceptibility of water: Observer.
The best modern determinations of the value of K for gaseous oxygen agree very fairly well with that given by Faraday in 18J3 (Exp. Res.
It is pointed out that this formula may be used as a temperature correction in magnetic determinations carried out in air.
The following table gives Curie's determinations (Journ.
According to the best determinations the value of elm does not exceed 1.8X Io', and T is of the order of Io 15 second, the period of luminous vibrations; hence OM/M must always be less than 109 H, and therefore the strongest fields yet reached experimentally, which fall considerably short of Io %, could not change the magnetic moment M by as much as a ten-thousandth part.
The distinction of the universal essence and the individualizing determinations in the individual does not coincide, he maintained, with the distinction between form and matter.
The additional determinations are as truly " form " as the universal essence.
Just as the genus becomes the species by the addition of formal determinations called the difference, so the species becomes the individual by the addition of fresh forms of difference.
For absolute determinations of wave-lengths plane gratings are used.
Marignac's name is well known for the careful and exact determinations of atomic weights which he carried out for twenty-eight of the elements.
In the ordinary chemical analyses of the soil determinations are made of the nitrogen and various carbonates present as well as of the amount of phosphoric acid, potash, soda, magnesia and other components soluble in strong hydrochloric acid.
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.
Recent determinations of the atomic weight of strontium are due to T.
The above method is especially useful for the determinations of very small capacities of the order of Ioo electrostatic units or so and upwards.
The above determinations at low temperature were made with either a steady or a slowly alternating electric force applied a hundred times a second.
Hydro- statical principles can be applied to density determinations in four typical ways: (I) depending upon the fact that the heights of liquid columns supported by the same pressure vary inversely as the densities of the liquids; (2) depending upon the fact that a body which sinks in a liquid loses a weight equal to the weight of liquid which it displaces; (3) depending on the fact that a body remains suspended, neither floating nor sinking, in a liquid of exactly the same density; (4) depending on the fact that a floating body is immersed to such an extent that the weight of the fluid displaced equals the weight of the body.
Methods depending on the free suspension of the solid in a liquid of the same density have been especially studied by Retgers and Gossner in view of their applicability to density determinations of crystals.
Travers, The Experimental Study of Gases (1901); and vapour density determinations in Lassar-Cohn's Arbeitsmethoden fur organisch-chemische Laboratorien (1901), and Manual of Organic Chemistry (1896), and in H.
A considerable amount of work has been done on determinations of the atomic weight of tellurium, the earlier results giving the value 128.
In determinations of stellar or solar parallax, comparison stars, symmetrically situated with respect to the object whose parallax is sought, should be employed, in which case the instantaneous scale-value may be regarded as an unknown quantity which can be derived in the process of the computation of the results.
All determinations must accordingly be reduced to a standard temperature for comparison.
The most easily observed is the freezing-point, and according to the very careful determinations of H.
The first useful determinations of the dissolved gases of sea-water were made by Oskar Jacobsen in 1872.
A temperature of 40.1 ° F., the carbonic acid amounts to 51 J5 cc. per litre, and the oxygen only to 2.19 cc. Vegetable plankton in sunlight can reverse this process, assimilating the carbon of the carbonic acid and restoring the oxygen to solution, as was proved by Martin Knudsen and Ostenfeld in the case of diatoms. Little is known as yet of the distribution of carbonic acid in the oceans, but the amount present seems to increase with the salinity as shown by the four observations quoted: Water from Gulf of Finland of 3.2 per mille salinity =17.2 cc. C02 Western Baltic of 14.2 North Atlantic of .0, , 49'0 Eastern Mediter ranean of 39.o, , =53'0, , Unfortunately the very numerous determinations of carbonic acid made by J.
To the infinitely actual there is necessary the possible; that which determines involves somewhat in which its determinations can have existence.
Later determinations were made by Sir T.