Popularly known as borax and properly designated as sodium tetraborate.

Properties : Sodium borate occurs as colorless, transparent crystals or a white powder, inodorous, and having a sweetish alkaline taste. It is soluble in water, but practically insoluble in alcohol.

Incompatibilities: Sodium borate is decomposed by mineral salts and is incompatible with mucilage of acacia, with the metallic salts of the mineral acids and with the salts of most alkaloids.

Action and Uses : Sodium borate is antiseptic, astringent and detergent and is used both externally and sometimes internally in the form of solution. The continuous ingestion of small doses produces a deleterious effect. Moderate to large doses may cause nephritis. Very large doses cause gastroenteritis, nephritis, skin eruptions, visual disturbances, fall of temperature, collapse and a wide-spread fatty degeneration. It is used in from 1 to 2 per cent, solution as an eye-wash in hyperemia of the conjunctiva and catarrhal conjunctivitis.

For this purpose the following formula is very serviceable :

Rx Sod. boratis............... 5                  gr. x

Aq. camph................ 10 3ii

Aq. dest. ad............... 25 oz j

It is sometimes used as an antipruritic solution:

Rx Sodii boratis ..............         1                     gr. xv

Glycerini...................         06 m χ

Aquae...................... 30 oz j

Dosage: 0.5 gm. or 7½ grains. It may be used as a gargle.