Put the vessels containing the precipitate aside, return the washings once through the asbestos so as to obtain them quite clear, remove them from the receiver, and set aside to recover the excess of silver. Rinse the receiver and complete the washing of the precipitate with about 200 cubic centimeters of cold water. Half of this is used to wash by decantation and the remainder to transfer the precipitate to the crucible with the aid of a trimmed feather. Finish washing in the crucible, the lumps of silver chlorid being broken down with a glass rod. Remove the second filtrate from the receiver and pass about twenty cubic centimeters of ninety-eight per cent alcohol through the precipitate. Dry at from 140° to 150°. Exposure for half an hour is found more than sufficient, at this temperature, to dry the precipitate thoroughly. (_b_) _Standard sulfuric acid_, the absolute strength of which has been determined by precipitation with barium chlorid and weighing the resulting barium sulfate: For ordinary work half normal acid is recommended, _i. e._, containing 18.2285 grams of hydrochloric or 24.5185 grams sulfuric acid to the liter; for work in determining very small amounts of nitrogen, one-tenth normal acid is recommended. In titrating mineral acids against ammonia solutions, use cochineal as indicator. (_c_) _Sulfuric acid_, specific gravity 1.84, free of nitrates and also of ammonium sulfate, which is sometimes added in the process of manufacture to destroy nitrogen oxids: (2) _Standard alkali_, the strength of which, relative to the acid, has been accurately determined. One-tenth normal ammonia solution, _i. e._, containing 1.7051 grams of ammonia to the liter, is recommended for accurate work: (3) _Metallic mercury_ or mercuric oxid, prepared in the wet way: That prepared from mercuric nitrate can not be safely used. (4) _Potassium permanganate_ finely pulverized: (5) _Granulated zinc_, pumice stone, or one-half gram of zinc dust is to be added to the contents of the flasks in distillation, when found necessary, in order to prevent bumping: (6) _Potassium sulfid._—A solution of forty grams of commercial potassium sulfid in one liter of water: (7) _Soda._—A saturated solution of sodium hydroxid free of nitrates: (8) _Indicator._—Solution of cochineal prepared as follows: Tincture of cochineal is prepared by digesting for a day or two, at ordinary temperatures, and frequently agitating, three grams of pulverized cochineal in a mixture of fifty cubic centimeters of strong alcohol with 200 cubic centimeters of distilled water. The solution is decanted or filtered through Swedish paper.