in the materia medica, the name of two species of marl used in medicine, viz. 1. The white kind, called by the ancients collyrium saminum, being astringent, and therefore good in diarrhoeas, dyteries, and haemorrhages; they also used it externally in inflammations of all kinds. 2. The brownish white kind, called oster famius by Dioscorides; this also stands recommended as an astringent.