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Knight's Mechanical Encyclopedia (ed. Knight) 51 15 Browse Search
George Ticknor, Life, letters and journals of George Ticknor (ed. George Hillard) 22 8 Browse Search
George Ticknor, Life, letters and journals of George Ticknor (ed. George Hillard) 7 1 Browse Search
Benjamnin F. Butler, Butler's Book: Autobiography and Personal Reminiscences of Major-General Benjamin Butler 3 1 Browse Search
Edward L. Pierce, Memoir and letters of Charles Sumner: volume 2 3 1 Browse Search
Thomas Wentworth Higginson, Olde Cambridge 2 2 Browse Search
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labor and research to benefit all mankind, particularly in the study of those sciences which were to test the magnetic and electric discoveries by Galvani, the results of whose researches were then being exploited by the great discoveries of Sir Humphry Davy. I believed that the gates for pursuing chemical knowledge and investigation in a regularly defined and scientific manner were opened by the wonderful invention of the murdered Lavoisier in his chemical nomenclature, which gave name and p This pile could readily be made in a student's room by building up plates of differently oxidizable metals with soft moistened porous mattings between them. It furnished power sufficient for electrical experiments in the same direction in which Davy, by a powerful battery of cells, was reducing into new combinations at will substances which had been hitherto deemed entirely simple and elementary. This substance, I believed, was the elective power of the future. At that time, so far as I kne
brated French chemist, first suggested the existence of the metallic bases of the earths and alkalies, which fact was demonstrated twenty years thereafter by Sir Humphry Davy, by eliminating potassium and sodium from their combinations; and afterwards by the discovery of the metallic bases of barytes, strontium, and lime. The earave been performed. The modern anaesthetic agents are: cold applications, protoxide of nitrogen (laughing-gas), chloroform, ether, amylene, kerosolene. Sir Humphry Davy suggested the use of protoxide of nitrogen as an anaesthetic agent in surgical operations. It was used by Dr. Wells of Hartford, Conn., in 1844, in dental o C′ I a frustrum to reflect upward the heat which reaches the inside of the tube. G′ is a perforated floor to prevent the conduction of flame, on the principle of Davy's safety-lamp. The water has an overflow down the central airtube. K is the base ring for the chimney. Dopp's Argand lamp. Ar-gent′al Mer′--cu-ry. Sil
(Carpentry.) A beam mortised into another to strengthen the building. Barge-course. (Architecture.) a. That portion of the shingling or slating of a roof which projects over the gable-end. b. A coping course of bricks laid edgewise and transversely on a wall. Bari. The portion of a roofing-slate showing the gage, and on which the water falls. Bar′i-tone. (Music.) A kind of bass-viol. Ba′ri-um. A metal, the base of heavy spar (sulphate of baryta), discovered by Davy. It is of a grayish or yellowish hue, has only been procured in very minute quantities, and is rapidly converted into an oxide by the action of either air or water. It has never been applied to any practical use in the arts. Equivalent, 68.5; symbol, Ba. An oxide of barium, when reduced to a white powder, is used to adulterate white lead, and also as a cosmetic, — both very bad practices; one injures the paint, and the other the complexion. Bark-cut′ting ma-chine′. Bark is r
e invention of this instrument has been credited to Roger Bacon, 1297, and to Alberti, 1437. It was described by Leonardo da Vinci, in 1500, as an imitation of the mechanical structure of the eye. The theory of optical sensation was laid down by Alhazen the Saracen, A. D. 1100. See binocular glasses. Baptista Porta, in 1589, mentions it in his book on Natural magic. Sir Isaac Newton remodeled it, 1700. Daguerre, in 1839, rendered the images obtained therein permanent, after Wedgewood, Davy, and Niepce had only partially succeeded. See photography. The camera-obscura as described by Baptista Porta is a dark chamber of cylindrical form, with a lens at one end and a white card or paper at the other, so placed as to be within the focus of the glass upon which the external image is depicted. The instrument, for the uses of photographers, has been enlarged and improved. Achromatic and periscopic glass have been employed; facilities for adjustment in hight, angle of presentat
re kept together by the suspending-chain, and are opened by their weighted arms as the boat touches the water. Fall-block hook. In Fig. 1597, the hook is capsized by a lever and a cord. Da′vy-lamp. (Mining.) The safety-lamp of Sir Humphry Davy, in which a wire-gauze envelope covers the flame-chamber and prevents the passage of flame outward to the explosive atmosphere of the mine, while it allows circulation of air, See safety-lamp. Day. The light of a window in a bay; the xture of about equal parts of the body to be oxidized, and nitrate or chlorate of potash or other energetic oxydizer. Def′la-grator. An instrument for producing intense heat. It is generally a form of the voltaic battery. Such was used by Davy in 1807 – 8, when he decomposed soda, potash, borax, and lime. In the form invented by Dr. Hare of Philadelphia, it is composed of a single sheet each of copper and zinc rolled helically upon a central cylinder of wood. The two metals are pre
on, which is discharged or caused to change color by electric action. Nicholson and Carlisle discovered, in 1800, that water was decomposed by the voltaic pile, hydrogen being evolved at the negative and oxygen at the positive end of the wire. Davy, afterwards Sir Humphry Davy, by the aid of the apparatus of the Royal Institution at London, the most powerful then in existence, proved by a series of experiments, commencing in 1801, that many substances hitherto considered as elementary bodiesSir Humphry Davy, by the aid of the apparatus of the Royal Institution at London, the most powerful then in existence, proved by a series of experiments, commencing in 1801, that many substances hitherto considered as elementary bodies could be decomposed by voltaic action, and succeeded in 1807 in resolving the fixed alkalies soda and potash. Faraday, 1833, besides his extensive additions to the science of electro-magnetism, established the fact that the chemical power of a current of electricity is in direct proportion to the absolute quantity of electricity which passes; and farther proved that the quantities required for decomposing compound bodies were proportional to the atomic weights of Dalton. Bain's telegraph (1
opper wire to the zinc of the next glass, and each transmits the electric current derived from the chemical action in its own glass, in addition to that derived from the action in the preceding glasses. The trough-battery c c′ was used by Sir Humphry Davy in his series of magnificent discoveries, 1806-8, when he isolated the metallic bases, calcium, sodium, potassium, etc. His trough had 2,000 double plates of copper and zinc, each having a surface of 32 square inches. It is like the compomospheres, and cold water be passed through the other receiver, the latter will exert a force of from 40 to 50 atmospheres. The difference in the pressures, say 45 atmospheres to the square inch, will be the power on the piston (at the start). Davy and Faraday, about 1823, succeeded in reducing several gases to a liquid state by means of great pressure and very low temperature. Upon releasing the pressure, the gases were found to again expand to their original volume. This discovery again
ton lens is of spherical form, and has a deep equatorial groove around it filled with opaque matter, acting as a diaphragm to diminish the quantity of light and exclude lateral rays. A spherical silica lens is ascribed to an experiment of Sir Humphry Davy. One end of a wheat straw is ignited, and the spear is allowed to consume grad- ually. The cinder is then heated in the blue flame of a burner, and from the silica obtained a solid globule of glass is formed, which is said to be well adaptdly revolved by gearing and handcrank, its periphery being in contact with a flint fixed to a holder on the frame. It was operated by a child, who waited upon the miner and lighted him at his work. It was superseded by the safety-lamp of Sir Humphry Davy. See safety-lamp. 5. Alum, sugar, and flour, when mixed and calcined, have a tendency to take fire when exposed to the atmosphere. Hence Homberg's pyrophorus. See pyrophorus. 6. Chlorate of potash mixed with sugar kindles into fla
icAs75755.8.0814Diamg125SchroederGr. Arsenikon (potent). BariumBa.68.5136.84887Davy1808Gr. Baros (heavy). BismuthBi.212210.349.823500.03081/719Diamg.161Agricola1517.0567Diamg.51175824Stromeyer1818Gr. Cadmia (calamine). CalciumCa.2040.211.578Davy1808Lat. Calx (lime). ChromiumCr.26.752.56.813,992Mag.5Vauquelin1797Gr. Chroma374.94081619Arfwedson1817Gr. Lithos (a stone). MagnesiumMg.,38215Davy1807Magnesia in Asia Minor. ManganeseMn.27.655.78.0133,452.01217Mag.4Gahn1740Mag1131Mag.9435603818Sp. dim. of Plata (silver). PotassiumK. Potash. RhodiumRo.52.2104.312.14,352.0580Diamg.14Wollaston1804Gr. Rhod.9310.531,832.05701/524Diamg.922400100100 SodiumNa.2323.040.972194.2934Diamg.636Davy1807Lat. Salsola (soda). StrontiumSr.4487.252.547Davy1808Strontian in Scotland.Davy1808Strontian in Scotland. TelluriumTe.64128.36.25752Muller1782Gr. Tellus (the earth) TinSn.591187.294428.05621/516Diamg4812484212 TungstenW.9418417.64,352.0334Diamg.16De Luyart1786Sw. Tu
jects. In 1802 he contributed a paper to the Journal of the Royal Institution of England, entitled An Account of a Method of copying Paintings upon Glass, and of making Profiles by the Agency of Light upon Nitrate of Silver; with Observations by H. Davy. He used white paper or white leather moistened with a solution of nitrate of silver, dried, and kept in a dark place. This, on being exposed to light, passed through different shades of gray and brown and became at length nearly black. When verge. Po′tance-file. A small hand-file with parallel and flat sides. Po-tas′si-um. Equivalent, 39.2; symbol, K (kalium); specific gravity, 0.865; fusing-point, 136° Fah. This metallic base of the alkali potassa was discovered by Sir Humphry Davy in 1807. It is a brilliant, silver-white metal, tarnishes immediately on exposure to the atmosphere; is soft at ordinary temperatures, brittle at 32° Fah. Its affinity for oxygen is so energetic that water is decomposed by contact, the libe<
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