BOTANIC MATERIA MEDICA. 331 
fore, is made up of .two distinct gums, termed 
Tragacanthin and Bassorin, together with a 
small quantity of starch, calcium carbonate, and 
3 per cent. of ash, 
' Tragacanth is principally imported from 
Smyrna and the Levant. Besides the afore- 
mentioned varieties, there are the Astragalus 
Microcephalus, A. Pycnocladus A. Stromatodes, 
and A. Aristatus, all of which varieties are lia- 
ble to find their way into the commercial world. 
