Nicotine (C14H10N2 = 160.96) is the principal alkaloid of Nicotiana tabaccum. It is decomposed, during the combustion of tobacco in smoking, into pyridine and other pyrrol products.* The toxicity of Nicotine to pyridine is in the ratio of 22 to 1.

Pharmacodynamics (of Tobacco when smoked).

Central Nervous System. - Higher centers are depressed; lower centers and cord are first irritated, then depressed.

Muscular System. - Actual ability diminished; reflex effect.

Respiration. - Slight acceleration, then slight slowing.

Heart. - Irregular after prolonged use; probably centric.

Blood-pressure is slightly elevated; centric (?)

Eye. - The optic nerve is irritated from continued use.

Alimentary Canal. - Primarily stimulated; later depressed.

Secretory Glands. - Primarily stimulated; later depressed.

Metabolism. - Some obscure interference, especially in youth.

Absorption takes place readily from the mucosa.

Excretion is carried on through the kidneys, lungs, and perspiration.

Local Action. - Irritant.

Tolerance. - Readily acquired in varying degrees by a majority of those who are sufficiently determined.

Symptoms.(produced by the smoking of Tobacco).

Before Tolerance.

Irritation of mucosa.

Altered vision.

Weakness.

Nausea.

Vomiting.

Prostration.

After Tolerance.

Impaired sense of taste and smell.

Rank, persistent characteristic odor from body and clothing.

Mucorrheas.

Dyspepsias.

Cardiac palpitation.

Visual disturbances.

Some muscular inco-ordinations.

Weakening of moral fiber.

Relative enfeeblement of will.

Diminished sense of personal responsibility.

Lowered mental capability.

Therapeutics.

Nicotine and Tobacco have no place whatever in applied medicine. Tobacco smoking is an unmixed evil to mankind.

* For experimental evidence on this point, see my article in N. Y. Medical Journal, March 14 1914: "Tobacco Smoking and Mental Efficiency."