See Aurum Stanno paratum, Pocket Formulary. Many other processes have been proposed, of which the following is one: - Dissolve 3 grs. of gold in aqua regia, avoiding excess, and dilute with 3 oz. of water. Mix 30 grs. of pink salt (the bichloride of tin with sal-ammoniac) with 3 1/4 grs. of tin filings and 2 drs. of water till the tin is almost entirely dissolved: add 7 drs. of water, and add this solution to the gold solution, slightly warmed. Wash the precipitate, and dry it.

cylinders, an acid liquor and tar are produced. These are received in proper reservoirs, and are afterwards separated. The tar is subjected to distillation, and yields oil of tar (containing creasote, eupiou, &c), and leaves a residium of pitch, or English asphalt. The acid liquor, separated from the tarry deposit, is also distilled: the first portion which comes over contains the pyroxlic spirit, which is rectified by one or more distillations. It may be further purified by distilling it with dried chloride of calcium, and finally with quicklime. This constitutes one of the articles sold under the name of naphtha, and is regarded by chemists as a hydrated oxide of methyle. After the pyroxylic spirit has come over, the crude pyroligneous acid distils, which still holds some tar and empyreumatic oil in solution. It is purified by saturating it either directly with common soda, or first with lime, or rather chalk, and when the neutral solution has become clear, evaporating it to 1.1l4 sp. gr., and adding sufficient saturated solution of sulphate of soda to decompose the impure acetate of lime. The clear solution obtained by either process is then evaporated, that the acetate of soda may crystallize. This is afterwards roasted at a temperature of about 500° Fahrenheit, to destroy the tar, and again dissolved and crystallized. The purified acetate is then distilled with sulphuric acid. See Acidum Aceticum, Pocket Formulary. For some manufacturing purposes, an impure acid is obtained by merely saturating the crude pyroligneous acid with lime, evaporating to dryness, and distilling with sulphuric acid.

If acetate of lime or acetate of lead be distilled without addition, and the liquid which comes over be rectified over lime, pyroacetic spirit is obtained: this is also termed acetone.