A dried paste prepared from the crushed or ground seeds of Paullinia sorbilis.

Characters. - Sub-globular, or elliptic cakes, or cylindrical sticks, hard, dark reddish-brown; fracture uneven, somewhat glossy, showing fragments of seeds invested with a black testa; odour slight, peculiar, resembling chocolate; taste astringent, bitter; it is partly soluble in water, and in alcohol.

Preparation.

Dose.

Extractum Guaranae Fluidum...............

...15 min. to 1 fl. oz.

Composition. - It contains four or five per cent. of caffeine (p. 870) and a considerable amount of tannic acid, and it is upon these that its medicinal value depends.

Uses. - It is chiefly used to cut short attacks of sick headache. It may be given in doses of one or two drachms of the powder, mixed with hot water, or as fluid extract, when the headache is coming on.