A volatile oil distilled from the fresh herb of Ruta graveolens.

Characters. - Pale yellow when recent; odour strong and disagreeable; taste, bitter, acrid.

Composition. - Consists of a hydrocarbon and an oil containing oxygen.

Dose. - 1 to 4 min. (0.06-0.3 c.c.)

Uses. - Externally it is rubefacient, internally it is stimulant, antispasmodic, emmenagogue, and carminative; used in amenorrhea, hysteria, convulsions, and flatulence.

Fig. 182. - Cusparia, half the natural size.