ZINO, ACETATE OP.—This salt is only of slight importance ; it is used medicinally, in a diluted state, as an astringent lotion, and, occasionally, in printing : it gives a fine orange-yellow on silk and cotton, but owing to its weak affinity for the fibre the colour is very unstable. It is obtained by calico-printers for their own use by dissolving 4 parts of sulphate of zinc and 7 of acetate of lead in hot water, allowing the sulphate of lead to settle out, and siphoning off the clear acetate.
It may also bo obtained in a pure state by dissolving metallic zinc in acetic acid, evaporating the solution, and crystallizing.
Acetic Ether ; ACETATE or ETHYL (GER. Essigatlgr ; Fe. Ether acitiqq,), discovered by Lau ragnais in 1759, is a fragrant, colourless liquid, possessing the agreeable odour of ether. It burns with a yellowish flame, and is soluble in water, alcohol, and ether. Heated with strong sulphuric acid it is eotivet ted into oxide of ethyl (common ether) and acetic acid : elbailled with a mixture of litnevvater and chloride of lime it yields chloroform. The density of the liquid is 3.089, and of the vapour Boiling point 73' (165" F.). Acetic ether may bo conveniently prepared by distilling together 3 pots of acetate of potash, 3 parts of absolute alcohol, and 2 parts of sul phuric acid. The distillate is mixed with a little water to separate the alcohol, and digested with chalk or carbonate of soda neutral. It is then agitated with chloride of calcium, or, pre ferably, with carbonate of potash, and finally re-distilled. During distillation care must be taken not to raise the temperature too rapidly. Upon a large scale acetate of lead is usually employed in place of acetate of potash iu the following proportions :-16 parts of white lead acetate, 6 parts of sulphuric acid, sp. gr, 1.81, 7 ports of absolute alcohol, and 5 parts of water.
Acetic ether is tined iu various medicinal preparations ; also for dissolving resins, sulphur, phos phorus, and essential oils in the preparation of varnishes. It is present in most wines.
Acetone ; PYROACETIO SPIRIT (Fa. Es7o•,7 pyro wetique; l ER. I'ssigy.0), first observed by Cour lent aux in 1754, is as substance given off in the destru tivo distillation of all the acetates. In its pure state it is a colourless liquid, similar in appearance and odour to acetic ether. It is highly inflammable, burning with a pale yellow, smokeless flame, and is miscible in all proportions with water, alcohol, and ether. The density of the liquid is 0.792, of the vapour The boiling point is 55.5° (132° F.).
Acetone is usually prepared by distilling acetate of lime or barium, carbonate of lime or barium remaining in the retort ; also by distilling dried acetate of lead in an earthenware, glass, or iron retort with quicklime, in the proportion of 2 pal is of the former to I of the latter. The crude product from the distillation of lead acetate is more or less contaminated with tar, and must be purified by saturation with carbonate of potash, and rectification with chloride of calcium. Aceteue is also produced in the destructive distillation of citric and tartaric acids, of sugar, starch, and various gums, with powdered quicklime.
Of the sources named the acetate of barium is the best, the distillate coming over perfectly colourless—almost pure acetone. The lime salt, like the lead, gives a more or less contaminated distillate, since it is only decomposed at a high temperature, when the tarry and empyreumatie compounds come over.
Acetone is used to a considerable extent in dissolving resins, gums, and camphors. It is also a solvent of the lower uitro-cellulose compounds. J. L.