A stearop-tene obtained by cooling the oil distilled from the fresh herb of Mentha arvensis, vars. piperascens et glabrata; and of Mentha piperita.

Characters. - Colourless crystals or masses, with a taste and smell of peppermint oil, sparingly soluble in water, readily soluble in alcohol, ether, and ethereal oils. When rubbed up with an equal quantity of thymol it forms a colourless oily liquid. The same is the case when it is rubbed with an equal quantity of pure carbolic acid or of chloral hydrate, or with butyl-chloral hydrate in the proportion of 1 part to 2 of menthol, or with camphor 2 parts to 3 of menthol. When boiled with sulphuric acid diluted with half its volume of water it becomes blue, the acid becoming brown.

Action. - It is a powerful antiseptic. When applied to mucous membranes or the skin it causes a feeling of warmth or burning, replaced by a feeling of coldness when the part is blown upon.

Uses. - It is chiefly used as an anti-neuralgic. It is either applied in the form of a solid pencil rubbed lightly over the part where the pain is felt, or an alcoholic solution, or the oily liquids prepared by trituration with camphor, carbolic acid, etc, may be painted over the painful spots. These oily liquids are also applied on cotton wool in order to relieve toothache.