A Text-book on Chemistry: For the Use of Schools and Colleges

Cover
Henry, 1868 - 507 Seiten
 

Was andere dazu sagen - Rezension schreiben

Es wurden keine Rezensionen gefunden.

Andere Ausgaben - Alle anzeigen

Häufige Begriffe und Wortgruppen

Beliebte Passagen

Seite 455 - The mass is then pressed, and boiled with water. On cooling, the solution precipitates a quantity of gallic acid, which may be purified by recrystallization. Like tannic acid, this substance yields no precipitate with a protosalt of iron, but a deep blue black with a persalt. It does not, however, precipitate gelatine; the crystals are soluble in one hundred parts of cold and three parts of boiling water ; the solution has an astringent taste. Gallic acid is used in photography for reducing silver...
Seite 110 - ... or convex, spherical, elliptical, paraboloidal, or any other figure. From the undulatory theory, the law of the refraction of light also follows as a necessary consequence. It is, " In every transparent substance, the sines of the angles of incidence and refraction are to each other in a constant ratio," and by the aid of this law we can determine the action of media bounded by surfaces of any kind, plane or spherical, concave or convex. It explains the action of lenses, and the construction...
Seite 367 - ... will prevent the metal from running away, and in a few minutes it will cool and take the impression, without the slightest injury to the paper from which it was taken.
Seite 257 - Fig. 240, in which ab is a bent tube, open at a and closed at b. The branch a may be several feet long, and b six inches. A small quantity of mercury is poured into the tube so as to occupy the bend, and shut up a column of air between d and b.
Seite 21 - ... gas" as a generic name for all elastic aeriform fluids. Of these gases he distinguished several kinds. He was also the first to adopt the melting point of ice and the boiling point of water as standards of the measurement of temperature. In his works the term "saturation...
Seite 165 - ... time through every transverse section of the circuit. The force of the current is directly proportional to the sum of the electro-motive forces which are active in the circuit, and inversely proportional to the total resistance of all its parts, or in other words the force of the current is equal to the sum of the electro-motive forces divided by the sum of the resistances.
Seite 364 - It crystallizes in rhomboids of blue color, with four atoms of water. It is soluble in four times its weight of cold, and twice its weight of hot water. It is an escharotic, an astringent, and has an acid reaction. With ammonia it forms a compound of a splendid blue color, which may be obtained in crystals; with potash, also, it forms a double salt. There are also subsulphates of copper.
Seite 422 - CeII<,S4 0+HO).— Hydrate of potassa is to be dissolved in twelve parts of alcohol, specific gravity .8, and bisulphide of carbon dropped into the solution until it ceases to have an alkaline reaction. On cooling to zero, the xanthate of potassa crystallizes ; it is to be dried in vacuo. It is soluble in water and alcohol, but not in ether, and from it xanthic acid may be procured by the action of dilute hydrochloric acid. Xanthic acid is an oily liquid, heavier than water, which first reddens and...
Seite 135 - ... deeply buried in the ground. This contrivance, the lightning rod, is now, as is well known, extensively applied. There are two theories respecting the nature of electricity : 1st, Franklin's theory, which assumes that there is but one fluid ; 2d, the theory of two fluids, called also Dufay's theory. Franklin's theory is, that there exists throughout all space a subtle and exceedingly elastic fluid, called the electric fluid, the peculiarity of which is, that it is repulsive of its own particles,...
Seite 366 - Lead is easily detected by sulphureted hydrogen, which throws it down from its solutions as a deep brown or black precipitate, and by the iodide of potassium or chromate of potassa, which give with it a yellow precipitate. Sulphuric acid yields with its salts a white insoluble sulphate of lead. SALTS OF THE PROTOXIDE OF LEAD. Carbonate of Lead — White Lead — Ceruse. — This salt forms as. a white precipitate when an alkaline carbonate is added to a solution of a salt of lead. Large quantities...

Bibliografische Informationen