Acetone, or Pyroacetic Spirit, and Pyroxilic Spirit, or Wood Naptha.—These are products of the distillation of wood, which are separated from the acid liquors after they are saturated with lime by simple distillation and rectification.
Owing to its cheapness, pyroxilic spirit has been extensively used in England, as a substitute for alcohol in the arts and manufactures.
Uses of Crude Pyroligneous Acid.—This acid having been incidentally described as the source of the acetic acid of commerce, it may be proper in this place to notice its uses. It acts on the principle of an antiseptic and a stimulant; the former property being chiefly due to the presence of creasote.
Several cases in which it was successfully employed in the preservation of animal matter are reported by Dr. T. Y. Simmons, of Charleston, S. C. The crude acid has been so advantageously used for the above purpose that Mr. Wm. Ramsey was led to perform with it some very interesting experiments. Some fresh fish, simply dipped in the acid and afterwards dried in the shade, were effectually preserved, and when eaten, at the end of eight months, were found very agreeable to the taste. Fresh beef, dipped in the acid in summer for the space of a minute, was perfectly sweet the following spring.
Carbolic Acid, or Phenylic Acid.—It occurs in castor and the urine of many domestic animals.
Coal tar is distilled, the product between 300° and 400° is saturated with a strong solution of potassa, the oil is removed, the salt decomposed by muriatic acid; the carbolic acid washed with water, dried with chloride of calcium, rectified, cooled to about 12° F., the liquid decanted and the crystals quickly dried. It is in long colorless needles; not very soluble in cold water; more so in hot water; in all proportions in alcohol and ether; also soluble in concentrated acetic acid.
Commercial Creasote.—When obtained from coal tar is always contaminated with phenylic acid (carbolic acid.) Indeed, it is said that phenylic acid has been sold for creasote, which it closely resembles in properties. How far these properties may be similar, deserves to be studied; for if they should prove to be the same, the fact would lead to its substitution as a substance to be easily obtained pure, for the variable creasote.
Of all the properties of creasote, the most remarkable is its power of preserving animal matter; this property has suggested its name, derived from two Greek words which mean flesh preserver. Dr. Christison finds that creasote water is as good a preservative of anatomical preparations as alcohol, with the advantage of not hardening the parts; it is probably to creasote that the antiseptic properties of pyroligneous acid are owing.
Tannic Acid.—Some powder of nut galls is macerated in a bottle, with just enough ether to moisten it, for 24 hours, and then expressed in a powerful press; and the process of maceration and expulsion is repeated in the same way until the powder is exhausted; the liquors are mixed, the ether distilled off, and the residue dried by means of a water bath.
Properties: Pure tannic acid is solid, uncrystallizable, white or slightly yellowish, inodorous; very soluble in water, and much less soluble in alcohol and ether, and insoluble in the fixed and volatile oils.