Aperient. A medicine which moves the bowels gently.

Aphthæ. Sore mouth, beginning in pimples and ending in white ulcers.

Aphthous. Complicated with aphthæ.

Apnoea. Short, hurried breathing.

Apoplexy. The effects of a sudden rush of blood to an organ; as the brain, lungs, etc. Brain pressure, from rupture of a blood-vessel.

Aqueous humor. The clear fluid contained in the front chambers of the eye.

Arachnoid. A thin, spider-web like membrane covering the brain.

Areolar Tissue. The network of delicate fibres spread over the body, binding the various organs and parts together.

Artery. A vessel carrying blood from the heart to the various parts of the body; usually red in color.