Nauseants.—Agents that induce nausea: aloes and white hellebore.

Antacids.—Agents that counteract acidity: soap and the carbonates of lime, magnesia, soda, and potash.

Alteratives.—Agents that bring about a healthy state of the system: aloes, calomel, cod-liver oil, sulphur, nitrate of potash.

Cardiacs.—Agents that invigorate the system by stimulating the stomach: Cayenne pepper, ginger, gentian, caraway seeds.

Demulcents.—Agents that lubricate or sheathe surfaces: glycerine, gum-arabic, linseed, and starch.

Antidotes.—Agents that counteract the effects of poisons: depending upon the kind of poison.

Medicines that Act upon the Brain, Nerves, and Nerve-centres.

Excitants.—Agents that stimulate the brain, nerves, and nerve-centres, and thus increase their energy: alcohol, ammonia, arnica, strychnia.

Narcotics.—Agents that are excitants, but whose action is followed by depression of energy: camphor, henbane, belladonna, opium.

Sedatives.—Agents that depress nervous power or lower circulation: digitalis, hydrocyanic acid, tartarated antimony, and chloroform.