Pharm. Also erron. thridach. [ad. mod.L. thridacium, f. Gr. θρίδαξ lettuce. Cf. F. thridace.] The inspissated juice of lettuce, used as a sedative; = LACTUCARIUM.
1831. J. Davies, Manual Mat. Med., 313. Thridace…. Juice furnished during the time of fructification by the Garden Lettuce, Lactuca sativa.
1836. J. M. Gully, Magendie’s Formul. (ed. 2), 164. The lactucarium of Dr. Duncan, and the thridach of Dr. François, are nothing more than the white, viscid juice of the garden lettuce … at the flowering time of the plant.
1857. Dunglison, Dict. Med. Sc., Thridace.
