The use of Calamus, Acorus calamus, in the domestic medication of India, is recorded from the very earliest times. It is sold commonly in the bazaars, and Ainslie (7) in his Materia Medica of Hindoostan, 1813, states that in consequence of its great value in the bowel complaints of children, a severe penalty was placed on the refusal of any druggist to open his door in the night to sell calamus, when demanded. The antiquity of its use is shown from the fact that it was one of the constituents of the ointment Moses was commanded to make for use in the Tabernacle, (Ex. xxx), while the prophet Ezekiel says of the commerce of Tyre, "Bright iron, cassia, and calamus were in thy market." Theophrastus (633) mentions calamus, and Celsus (136), nearly two thousand years ago, refers to it as a drug from India. In the sixteenth century Amatus Lusitanus (16a) reports it as imported into Venice, and in 1692 Rheede (547) figures it as an Indian plant under the name Vacha, the same name being still applied to it on the Malabar Coast. From its tropical home calamus has spread until it is now found in all temperate climates suitable for its growth, the market supply coming mainly from Southern Russia, through Germany. The therapeutic use of calamus in pharmacy and licensed medicine is, as with other like substances, a gift of empiricism founded in the far distant past.