Note 566 — PHARMACOLOGIA. (continued 5)

This variety of gum, which is characterised by its gelatinizing, but not dissolving, in water, occurs in several vegetable substances; and as it predominates in the Cherry-tree, Dr. John has distinguished it by the name of Cerasin; but as Tragacanth consists almost entirely of this substance, the term Tragacanthin would have been much more appropriate. Although Cerasin will not dissolve in pure water, it undergoes solution in that menstruum, at the temperature of ebullition, provided a portion of a mineral acid be added.