Properties : Boric acid forms transparent, colorless scales or a light, unctuous, very fine powder. It is odorless, has a faintly bitter taste and is slowly soluble in water (1 :18) and soluble in alcohol (1:15).

Action and Uses: Boric acid is a mild antiseptic. It has been occasionally administered internally, but with little effect, in cystitis. Externally it is frequently used as a dusting powder, either alone or combined with diluents such as starch or talcum, or with active substances such as acetanilid, salicylic acid or iodoform. It is also widely used as a wash or lotion, especially for catarrh of the mucous membranes, cystitis, conjunctivitis, pharyngitis, etc., usually in simple aqueous solutions containing from 2 to 4 per cent, of boric acid. This is one of the most frequently used lotions for conjunctivitis. It is also very useful for irrigating the bladder in cystitis. It is used in the form of glycerite of boroglycerin in washes and injections. The ointment is mildly antiseptic but is chiefly used as a protective dressing.

Glyceritum Boroglycerini.—Glycerite Of Boroglycerin, U. S. P

A Glycerin Solution Representing 30 Per Cent, Of Boric Acid.

Unguentum Acidi Borici.—Ointment Of Boric Acid, U. S. P.

A 10 per cent, mixture of boric acid with paraffin and white petrolatum.