Serous membrane.—The lining of cavities which have no external opening.

Seton.—An opening in the flesh made and continued by drawing through a skein of silk or linen thread or horsehair.

Siesta.—A midday nap.

Silicea.—Pure flint.

Sitz-bath.—A bath in a sitting position.

Sphincter muscle.—Circular, contracting muscle.

Sperm.—Seed. Fecundating principle.

Sputa.—Matter coughed up from throat and lungs. Phlegm.

Sterility.—Barrenness.

Stertorious.—Stertorous. Deep. Labored. Snoring.