Watt, Electro-Plating and Electro-Refining of Metals (London, 1902); W.
Among the educational institutions are the Albany Medical College (1839) and the Albany Law School (1851), both incorporated since 1873 with the Union University, the Collegiate Department of which is at Schenectady; the Albany College of Pharmacy (1881), also part of Union University; the Albany Academy (1813), in which Joseph Henry, while a member of the faculty, perfected in 1826-1832 the electro-magnet and began his work on the electric telegraph; the Albany Academy for Girls, founded in 1814 as the Albany Female Academy (name changed in 1906); and a State Normal College (1890), with a Model School.
The analytical treatment of such vortex rings is the same as for the electro-magnetic effect of a current circulating in each ring.
In 1883 he went to Kiel, becoming Privatdozent, and there he began the studies in Maxwell's electro-magnetic theory which a few years later resulted in the discoveries that rendered his name famous.
His boyhood was spent at Munich where his father, who owned electro-technical works, settled in the early 'eighties.
The first requisite for electro-telegraphic communication between two localities is an insulated conductor extending from one to the other.
The movements of the shaft are controlled by relays and electro-magnets which operate in response to the action of the subscriber whose telephone is fitted with a 'calling mechanism which, when the subscriber calls, earths the line a certain number of times for each figure in the number of the wanted subscriber.
Newlands in England, that if they are arranged in the order of their atomic weights they fall into groups in which similar chemical and physical properties are repeated at periodic intervals; and in particular he showed that if the atomic weights are plotted as ordinates and the atomic volumes as abscissae, the curve obtained presents a series of maxima and minima, the most electro-positive elements appearing at the peaks of the curve in the order of their atomic weights.
Those elements which are disengaged at the negative pole are termed electro-positive, or positive, or basylous elements, whilst those disengaged at the positive pole are termed electro-negative, or negative, or chlorous elements.
Its systematic name is formed by replacing the last syllable of the electro-negative element by ide and prefixing the name of the other element.
Instances had already been recorded of cases where a halogen element replaced hydrogen with the production of a closely allied substance: Gay Lussac had prepared cyanogen chloride from hydrocyanic acid; Faraday, hexachlorethane from ethylene dichloride, &c. Here the electronegative halogens exercised a function similar to electro-positive hydrogen.
Among other important articles of domestic industry are tobacco and cigars (manufactured mainly in bond, within the free harbour precincts), hydraulic machinery, electro-technical machinery, chemical products (including artificial manures), oils, soaps, india-rubber, ivory and celluloid articles and the manufacture of leather.
The electro-deposition of brass-mainly on iron ware, such as bedstead tubes-is now very widely practised, the bath employed being a mixture of copper, zinc and potassium cyanides, the proportions of which vary according to the character of the brass required, and to the mode of treatment.
Miscellaneous Effects of Magnetization: Electric Conductivity - Hall Effect - Electro-Thermal Relations - Thermoelectric Quality - Elasticity - Chemical and Voltaic Effects.
The total magnetic induction or flux corresponds to the current of electricity (practically measured in amperes); the induction or flux density B to the density of the current (number of amperes to the square centimetre of section); the magnetic permeability to the specific electric conductivity; and the line integral of the magnetic force, sometimes called the magnetomotive force, to the electro-motive force in the circuit.
[[[Magnetic Measurements]] introduced the method of measuring hysteresis by means of an electro-dynamometer used ballistically.
Electro-Thermal Relations.-The Hall electromotive force is only one of several so-called " galvano-magnetic effects " which are observed when a magnetic field acts normally upon a thin plate of metal traversed by an electric current.
Round the molecule until the field is withdrawn, when it will be stopped by the action of an electro-motive force tending to induce an exactly equal current in the opposite direction.
Nine memoirs, entitled "Electro-Physiological Researches," were published in the Philosophical Transactions, 1845-1860.
Moreover, his association with glass manufacture led him to study the refractive indices of different kinds of glass; he further undertook abstruse researches on electrostatic capacity, the phenomena of the residual charge, and other problems arising out of Clerk Maxwell's electro-magnetic theory.
Zinc being more electro-positive even than nickel, all the heavy metals must be removed before its deposition is attempted.
Borchers, trace it to the presence of oxide, produced, for example, either by the use of a solution containing a trace of basic salt of zinc (to prevent which the bath should be kept just - almost imperceptibly - acid), or by the presence of a more electro-negative metal, which, being co-deposited, sets up local action at the expense of the zinc. Many processes have been patented, the ore being acted upon by acid, and the resulting solution treated, by either chemical or electrolytic means, for the successive removal of the other heavy metals.
A rod of perfectly pure zinc, when immersed in dilute sulphuric acid, is so very slowly attacked that there is no visible evolution of gas; but, if a piece of platinum, copper or other more electro-positive metal be brought into contact with the zinc, it dissolves readily, with evolution of hydrogen and formation of the sulphate.
Other sources of employment are the cutting of hair for making hats, the production of fancy goods, type, machinery, soap and perfumery, ready-made clothing, chemicals, electro-technical apparatus, jewelry and metal wares.
For the theory and elemental laws of electro-deposition see Electrolysis; and for the construction and use of electric generators see Dynamo and Battery: Electric. The importance of the subject may be gauged by the fact that all the aluminium, magnesium, sodium, potassium, calcium carbide, carborundum and artificial graphite, now placed on the market, is made by electrical processes, and that the use of such processes for the refining of copper and silver, and in the manufacture of phosphorus, potassium chlorate and bleach, already pressing very heavily on the older non-electrical systems, is every year extending.
Soluble impurities which are more electro-negative than the metal under treatment must, if present, be removed by a preliminary process, and the voltage and other conditions must be so selected that none of the more electro-positive metals are co-deposited with the metal to be refined.
(Leipzig, 1900); Gore, The Art of Electrolytic Separation of Metals (London, 1890); Blount, Practical Electro-Chemistry (London, 1906); G.
Bismuth is extracted from its ores by dry, wet, or electro-metallurgical methods, the choice depending upon the composition of the ore and economic conditions.
Fremont is situated in a good agricultural region; oil and natural gas abound in the vicinity; and the city has various manufactures, including boilers, electro-carbons, cutlery, bricks, agricultural implements, stoves and ranges, safety razors, carriage irons, sash, doors, blinds, furniture, beet sugar, canned vegetables, malt extract, garters and suspenders.
When contact was made it completed an electric circuit which passed to a recording station, and there, by means of an electro-magnet, actuated a style writing a record on a band of travelling smoked paper.
If the wheel has very little work to do it may not be necessary to apply driving power, and uniform rotation may be maintained by the electro-magnet.
In a common form of electrically maintained fork, the fork is set horizontal with its prongs in a vertical plane, and a small electro-magnet is fixed between them.
The circuit of the electro-magnet is made and broken by the vibration of the fork in different ways - say, by a wire bridge attached to the lower prong which dips into and lifts out of two mercury cups.
A field of electro-mechanical mines was laid by the Japanese in the night of April 12th-13th, and on the following day the Japanese cruisers stood inshore to tempt Arthur.
Although he received some instruction from John Dalkon in chemistry, most of his scientific knowledge was selftaught, and this was especially the case with regard to electricity and electro-magnetism, the subjects in which his earliest researches were carried out.
By rot ting a small electro-magnet in water, between the poles of ano her magnet, and then measuring the heat developed in the wat r and other parts of the machine, the current induced in the coils, and the energy required to maintain rotation, he cal b lated that the quantity of heat capable of warming one you d of water one degree F.
A characteristic property of the alkaline fluorides is their power of combining with a molecule of hydrofluoric acid and with the fluorides of the more electro-negative elements to form double fluorides, a behaviour not shown by other metallic halides.
In this place it must suffice to indicate the gist of the more recent developments of the electro-optical theory, which involve the dynamical verification of Fresnel's hypothesis regarding optical convection and the other relations above described.
In 1788 the first woollen mill in New England was opened in Hartford; and here, too, about 1846, the Rogers process of electro-silver plating was invented.
Cruikshank was already experimenting with a process of electro-plating, and in 1837 Mr Spencer in England, and in 1838 Professor M.
Wade (loc. cit.) explains the formation of nitriles from potassium cyanide, and of isonitriles from silver cyanide by the assumption that unstable addition products are formed, the nature of which depends on the relative state of unsaturation of the carbon and nitrogen atoms under the varying conditions: KNC--KN :C(:C 2 H 5 I) --SKI +C2H5CN, AgNC->AgN(:C2H51)C---AgI-f-C2H5NC; that is, when the metal is highly electro-positive the carbon atom is the more unsaturated, the addition takes place on the carbon atom, and nitriles are produced.
On the other hand, when there is but little electro-chemical difference between the radical of the cyanide and that of the reacting compound then the nitrogen atom is the more unsaturated element and.
Azoxybenzene is also found among the electro-reduction products of nitrobenzene, when the reduction is carried out in alcoholic-alkaline solution.
The temperature of the sun and of the electric spark, others again with electro-photometry and the chemistry of the electric arc. With Professor J.
Phillips, the editor of the Annals of Philosophy, wrote for that journal an historical sketch of electro-magnetism, and he repeated almost all the experiments he described.
This first success of Faraday in electro-magnetic research became the occasion of the most painful, though unfounded, imputations against his honour.
The case of electro-magnetic forces between two conductors carrying electric currents affords an example of a statement of motion in terms of force of a highly artificial kind.
The highly electro-positive character of aluminium is most important.
On the other hand, its electro-positive nature necessitates some care in its utilization.
Abraham Bennet, the inventor of the gold leaf electro e described a doubler or machine for multiplying Bennet'.
Two years later he first tried the effect of electro-puncture of the muscles on a patient under his care, and from this time on devoted himself more and more to the medical applications of electricity, thereby laying the foundation of the modern science of electro-therapeutics.
1907.19o8.i f907.1908i Electro-technical products 411 451 8,227 9,107
The introduction of gas as an illuminant, about 1816, at once induced a large demand and a novel description of metal fitting; and the craft fell under the control of a new commercial class, intent on breaking with past traditions, and utilizing steam power, electro-deposition, and every mechanical and scientific invention tending to economize metal or labour.
Gilding, stains and lacquers, electro-plating, chasing, "matting," frosting, burnishing, mechanically produced mouldings and enrichments, and the other processes esteemed in the 10th century, are disused and avoided.
The subdued colour and soft contours of pewter render it once more a favoured material, peculiarly adapted to the methods of the art revival, and perhaps destined to supersede electro-plate for household purposes.
In some cases the whole object is a modern reproduction in electro-plate, but more often really old articles from which the original plating has been worn off in course of time have been replated, both equally being in the eyes of the connoisseur, unworthy of serious attention and comparatively valueless.