A concrete resinous exudation obtained by making incisions in the bark of the stem and large branches of Pistacia Lentiscus. Scio.

Characters. - Globular or elongated tears about the size of a pea, pale yellow, glass-like, brittle, becoming soft and plastic when chewed; faint agreeable odour and slight terebinthinate taste.

Composition. - Consists of about 90 per cent. of an acid resin (mastichic acid), soluble in alcohol; the remaining 10 per cent. is masticin, a tenacious resin soluble in ether, with traces of an ethereal oil.

Preparation.

u.s.p.

Pilulfae Aloes et Mastiches (vide p. 523).

Dose. - 20 to 40 gr. if administered internally.

Uses. - It is sometimes chewed in order to give a pleasant odour to the breath. It is chiefly employed for temporarily stopping decayed teeth, and for arresting haemorrhage from leech-bites. When used to stop teeth the cavity ought to be well cleaned and dried, and a piece of cotton saturated with a solution of four parts of mastiche should be gently pressed into it so as not to cause pain, but to fill the cavity exactly. Another method is to dissolve one part of mastiche with two of collodion, and fill the cavity with this. Either of these methods may also be employed to stop bleeding from leech-bites. It has been supposed to have a stimulating action on the bronchial mucous membrane, and has been used in bronchorrhoea, and also in infantile cholera. It is used to cover mercurial pills and prevent the formation of amalgam when they are silvered. When mixed with aloes it renders the pill less readily soluble, and so to exert an action more on the lower than upper part of the intestine.