AMYL NITRITE (isoamyl nitrite), a liquid which finds application in medicine, since it reduces blood pressure and re tards the pulse. It is prepared by passing nitrous fumes (from starch and concentrated nitric acid) into warm isoamyl alcohol; or by distilling a mixture of 26 parts of potassium nitrite in 15 parts of water with 3o parts of isoamyl alcohol in 3o parts of sul phuric acid. It is a yellow-coloured liquid of specific gravity 0.877, boiling at about 95°-96° C, of characteristic penetrating odour, and having the composition It is insoluble in water, but dissolves readily in alcohol, ether, glacial acetic acid, chloroform or benzene. It is easily decomposed by nascent hydrogen, with the formation of ammonia and isoamyl alcohol; and on hydrolysis with caustic potash it forms potassium nitrite and isoamyl alcohol. When the liquid is dropped on to fused caustic potash, it forms potassium valerate.