Ether is an alcohol derivative.

Chloroform is obtained by the action on alcohol of calcium hydroxide and bleaching powder.

Pharmacodynamics.

Central Nervous System. - Ether and Chloroform produce a progressive downward paralysis of the nervous system, the medulla being the last affected; sensory and receptive synapses are affected before the motor.

Muscular System. - No direct action.

Respiration. - Temporarily slowed from trigeminus and vagus reflex. Slowing in third stage due to depression of medulla.

Heart. - Auricles progressively weakened; ventricles slowly dilated from toxic effect. Action much more pronounced with Chloroform.

Blood-pressure rises, then slowly falls under ether; falls ab initio and steadily with Chloroform. Local irritation produces vascular relaxation, especially in splanchnic area; this effect is more marked with Chloroform than with Ether.

Pupil. - Early dilatation; secondary contraction; coma dilatation.

Alimentary Tract. - Irritated through fat-solvent action.

Secretory glands of mouth irritated reflexly.

Metabolism. - Chloroform tends to induce fatty infiltrations, especially of the liver, through its solvent action. Ether tends to induce pulmonic complications, through lowering of vital resistance.

Absorption is exceedingly rapid through the lungs.

Excretion is through the lungs; prolonged with Ether.

Temperature is lowered through specific heat vaporization, and from lessened heat production.

Local action is irritant, especially if vapor is confined.

Symptoms.

1st Stage:

Dyspnea and sense of asphyxia.

Mental incertitude.

Diminished aesthesia.

Roaring in the ears.

Enlarged pupil.

Slightly accelerated pulse. 2d Stage:

Aberrancies of consciousness.

Erratic, inco-ordinated muscle movements.

Rambling, disconnected, abnormal loquacity.

Irregular respirations.

Flushed skin.

3d Stage:

Profound sleep.

Muscular relaxation.

Reflexes disappear.

Excessive secretion of saliva, with Ether.

Diminished force and frequency of pulse.

Flushing of face with Ether; pallor with Chloroform.

Respirations becoming slower and shallower.

Temperature gradually falls.

Pupil becomes constricted.

Chloroform is three times as depressant as Ether, and eight times as toxic.

Therapeutics.

Ether and Chloroform are used principally as general anaesthetics.

Crimson = stimulation. Violet = depression.