The purgatives may be arranged in three subdivisions, the vegetable, the saline, and the mercurial.

In this subdivision I include castor oil, rhubarb, aloes, butternut, senna, American senna, jalap, and may-apple; though, in regard to jalap and may-apple, the propriety of this position may be considered doubtful, as they have hydragogue properties and a certain amount of acrimony, which render them closely analogous to the drastics, from which they differ only in being somewhat milder.

* In relation to the influence of magnesia on the system, a fact has been reported of no little interest if substantiated; that the salts of magnesia are absolutely wanting in certain localities in Lombardy where goitre is most frequent. The report was transmitted to the Paris Academy of Sciences by Marshal Vaillant, on the part of Dr. Demortain, "pharmacien en chef," of the French Army of Italy, at the meeting of Oct. 17, 1859. {Arch. Gén., Dec. 1859, p. 746.) - Note to the third edition.