§ 165. =Amylic Alcohol=--_Formula_, C₅H₁₁HO.--There is more than one amylic alcohol according to theory; eight isomers are possible, and seven are known. The amylic alcohols are identical in their chemical composition, but differ in certain physical properties, primary amylic alcohol boiling at 137°, and iso-amyl alcohol at 131·6°. The latter has a specific gravity of ·8148, and is the variety produced by fermentation and present in fusel oil. § 166. The experiments of Eulenberg[153] on rabbits, Cross[154] on pigeons, Rabuteau[155] on frogs, and Furst on rabbits, with those of Sir B. W. Richardson[156] on various animals, have shown it to be a powerful poison, more especially if breathed in a state of vapour. [153] _Gewerbe Hygiene_, 1876, p. 440. [154] _De l’Alcohol Amylique et Méthyl sur l’Organisme (Thèse)_, Strasburg, 1863. [155] “Ueber die Wirkung des Aethyl, Butyl u. Amyl Alcohols,” _L’Union_, Nos. 90, 91, 1870. Schmidt’s _Jahrb._, Bd. 149, p. 263. [156] _Trans. Brit. Association_, 1864, 1865, and 1866. Also, _Brit. and Foreign Med. Chir. Rev._, Jan. 7, 1867, p. 247. Richardson, as the result of his investigations, considers that amyl alcohol when breathed sets up quite a peculiar class of symptoms which last for many hours, and are of such a character, that it might be thought impossible for the animal to recover, although they have not been known to prove fatal. There is muscular paralysis with paroxysms of tremulous convulsions; the spasms are excited by touching the animal, breathing upon it, or otherwise subjecting it to trifling excitation. § 167. Hitherto, neither the impure fusel oil, nor the purer chemical preparation, has had any toxicological importance. Should it be necessary at any time to recover small quantities from organic liquids, the easiest way is to shake the liquid up with chloroform, which readily dissolves amylic alcohol, and on evaporation leaves it in a state pure enough to be identified. Amyl alcohol is identified by the following tests:--(1) Its physical properties; (2) if warmed with twice its volume of strong sulphuric acid, a rose or red colour is produced; (3) heated with an acetate and strong sulphuric acid, _amyl acetate_, which has the odour of the jargonelle pear, is formed; (4) heated with sulphuric acid and potassic dichromate, valeric aldehyde is first produced, and then valeric acid is formed; the latter has a most peculiar and strong odour.