Toxicology, derived from the Greek Toxikon, a poison, is that branch of knowledge which treats of the nature, actions, detection and treatment of poisons.
A medicine is an agent of animal, vegetable, or mineral origin used for the cure of disease or relief of pain.
Drug, derived from the Dutch, Droog, meaning dry, is now used synonymously with medicine although originally referring to an herb or dried medical plant.
GENERAL ACTIONS OF MEDICINES
Alterative.—A medicine that alters the process of nutrition, so as to overcome morbid conditions of the body as Arcenous Acid, Potassium Iodide, etc.
Anaesthetic.—Medicines used to produce insensibility to pain, and they are divided into Local and General Anaesthetics.
General Anaesthetics.—Are inhaled and carried by the blood to the brain and spinal cord, where they paralyze the nerve centers, cause muscular relaxation and finally produce entire suspension of sensation and power of motion, together with a loss of consciousness, and apparent life, except breathing and the action of the heart. They comprise Nitrous Oxide Gas, Ether and Chloroform, etc.
Local Anaesthetics.—As a rule, are injected hypodermically or applied to open wounds. They cause temporary loss of local or circumscribed sensation by paralyzing the sensory nerves. When applied in the form of liniments they resemble anodynes, but act more promptly and profoundly. They comprise Cocaine, Eucaine, etc.
Analgesic.—A medicine used to relieve pain, as Opium, etc.
Anaphrodisiac.—A medicine used to produce absence or impairment of sexual appetite, as Potassium Bromide, etc.