Gossypium - Cotton Wool. - The hairs of the seed of several species of Gossypium, carded.

Preparations.

Pyroxylin. Gun Cotton. - Made by immersing the wool in a mixture of sulphuric and nitric acids, washing, draining, and drying.

From Pyroxylin is prepared:

Collodium. - Made by dissolving Pyroxylin, 1; in Ether, 36; and Rectified Spirit, 12.

From Collodium is prepared:

Collodium Flexile. - Collodium, 48; Canada Balsam, 2; and Castor Oil, 1.

Non-officinal Preparation of Gossypium.

Absorbent Cotton Wool. Cotton wool deprived of its oil by washing with an alkali.

Action And Uses

The action and uses of cotton wool in medical and surgical practice are sufficiently familiar. Absorbent cotton is now much employed.

Pyroxylin is introduced for the purpose of making collodion.

Collodion, when painted on the skin or other exposed part, instantly dries by evaporation of the ether, forming a fine film. This film serves as a protective to thin, inflamed, broken, or incised surfaces, preventing bed-sores, arresting haemorrhage (as in leech-bites), and closing fissures or punctures made with aspirateurs or trochars in paracentesis. The flexible collodion does not contract on drying or readily crack, and is a better form for most of the above purposes.