In Class C we have a large and valued list of cathartics, and these may be subdivided for convenience of study into several small groups. These are.:

(a) Bile and bile-salts.

(b) The fixed oils and their products (soap and glycerin).

(c) The mercurials.

(d) The anthracene derivatives.

(e) Acids, resins, and glucosides with drastic action - the drastics.