It is common to add to purified wood vinegar, a little acetic ether, or caramelised (burnt) sugar to colour it, also, in France, even wine, to flavour it. Its blanching effect upon red cabbage, which it has been employed to pickle, is owing to a little sulphurous acid. This may be removed by redistillation with peroxide of manganese. Indeed, Stoltze professes to purify the pyrolignous acid solely by distilling it with peroxide of manganese, and then digesting it with bruised wood charcoal; or by distilling it with a mixture of sulphuric acid and manganese. But much acid is lost in this case by the formation of acetate of that metal.
Birch and beech afford most Pyrolignous acid, and pine the least. It is exclusively employed in the arts, for most purposes of which it need not be very highly purified. It is much used in calico printing, for preparing acetate of iron called Iron Liquor, and acetate of alumina, called [Red Liquor]; which see. It serves also to make sugar of lead; yet when it contains its usual quantity, after rectification, of tarry matter, the acetate of lead will hardly crystallise, but forms cauliflower concretions. This evil may be remedied, I believe, by boiling the saline solution with a very little nitric acid, which causes the precipitation of a brown granular substance, and gives the liquor a reddish tinge. The solution being afterwards treated with bruised charcoal, becomes colourless, and furnishes regular crystals of acetate or sugar of lead.
Pyrolignous acid possesses, in a very eminent degree, anti-putrescent properties. Flesh steeped in it for a few hours may be afterwards dried in the air without corrupting; but it becomes hard, and somewhat leather-like: so that this mode of preservation does not answer well for butcher’s meat. Fish are sometimes cured with it. See [Pyro-acetic Spirit]; Pyroxilic Ether; [Pyroxolic Spirit]; [Pyrolignous Acid] and [Vinegar].
ACETIMETER. An apparatus for determining the strength of vinegar. See the conclusion of the [preceding article] for a description of my simple method of acetimetry.
ACETONE. The new chemical name of [pyro-acetic spirit].
ACID OF ARSENIC. (Acide Arsenique, Fr.; Arseniksäure, Germ.)
ACIDS. A class of chemical substances characterised by the property of combining with and neutralising the alkaline and other bases, and of thereby forming a peculiar class of bodies called salts. The acids which constitute objects of special manufacture for commercial purposes are the following:—[acetic], [arsenious], [carbonic], [chromic], [citric], [malic], [muriatic], [nitric], [oxalic], [phosphoric], [sulphuric], [tartaric], which see.
ACROSPIRE. (Plumule, Fr.; Blattkeim, Germ.) That part of a germinating seed which botanists call the plumula, or plumes. See [Beer] and [Malt].
ADDITIONS. Such articles as are added to the fermenting wash of the distiller are distinguished by this trivial name.