alum

Evidence

"the Sayadelah (pharmacists) introduced new drugs such as... alum..."

Remarks

Alum is identified as one of the new substances introduced by Islamic pharmacists (Sayadelah) during the 9th-century Abbasid period (p. 106). Although described here as a medicinal product, alum was historically vital in manuscript production as a mordant for lake pigments and as a sizing agent for paper.