Gilding Solution.--To one pint of pure rain or distilled water add fifteen grains of pure chloride of gold, and to another pint add sixty grains of hyposulphite of soda. When dissolved, pour the gold solution into the hyposulphite by small quantities, shaking well after each addition. The soda solution must not be poured into the gold, as the gold would be immediately decomposed, and the solution turn black, and be unfit for use.英文原著 · 《American Hand Book of the Daguerreotype》
Preparation.--The mother-liquor containing bromides is treated with a current of chlorine gas, which decomposes these salts, setting the bromine free, which at once colors the liquid to a reddish brown color. Ether is added and shaken with the liquid, until all the bromine is taken up by the ether, which acquires a fine red color and separates from the saline liquid.英文原著 · 《American Hand Book of the Daguerreotype》
silver, a light yellowish white precipitate of bromide of silver, which is insoluble in an excess of acid, and readily dissolves in ammonia. The precipitated bromide is colored by light like the chloride, but is immediately tinged brown, while the chloride assumes at first a violet hue. The bromides, in solution, are readily decomposed and chloride being set free, colors the liquid brown.英文原著 · 《American Hand Book of the Daguerreotype》
Bromide of Silver--May be formed by pouring an alkaline bromide into a solution of nitrate of silver, in the shape of a white, slightly yellowish precipitate, which is insoluble in water and nitric acid, but readily dissolves in ammonia and the alkaline hyposulphites. Chlorine easily decomposes bromide of silver, and transforms it into chloride.英文原著 · 《American Hand Book of the Daguerreotype》
Iodides.--The iodide treated with the oil of vitriol, instantly produces a considerable deposit of iodine; and if the mixture be heated, intense violent vapors are disengaged. The reaction is due to the decomposition of oil of vitriol by iodohydric acid, water and sulphurous acid being formed, and iodine set free. The iodides in solution are decomposed by chlorine, iodine being precipitated, the smallest quantity of which in solution is instantly detected by its imparting to starch an intensely blue color.英文原著 · 《American Hand Book of the Daguerreotype》
"For small operations, those invaluable vessels, Florence flasks, answer well: a bent tube being connected at one end to its month, the other passing into the second vessel; heat should be cautiously applied by means of an Argand lamp, a little vessel of sand being placed under the flask, which helps the acid to decompose the salt. Prussic acid is then generated and passes through the tube to the recipient vessel, which is to be charged with liquor potassae.英文原著 · 《American Hand Book of the Daguerreotype》