Origin and Composition. Though with two equivalents of acid in its composition, borax has still alkaline properties, and probably owes whatever medical virtues it may possess mainly to the predominance of power in its base. it, therefore, properly belongs to the present class. it consists of two equivalents of boracic acid, one of soda, and either ten or five of water, according to its crystalline form; the ordinary prismatic crystals containing the former number, and the octohedral, which is a rarer form, the latter. The salt is procured, in an impure state, from certain lakes in the interior of Asia, and is afterwards prepared for use. For the modes of purifying it the reader is referred to Dr. Bache's article on borax in the U. S. Dispensatory. it is also prepared artificially by treating boracic acid, obtained from certain lagoons in Tuscany, with carbonate of soda.

Properties

Borax is in white, six-sided prismatic crystals, terminating in three-sided pyramids. it is of a sweetish, slightly alkaline taste, fusible by heat, slowly efflorescent, soluble in 12 parts of cold and 2 of boiling water, and with an alkaline reaction. it increases the solubility of cream of tartar, and coagulates mucilage, producing with it a tremulous jelly, which is redissolved by syrup.

Medical Effects and Uses

This salt was probably used by the ancients, though in an impure state. Not a little difference of opinion has existed as to its effects on the system. With mild refrigerant properties, it has been supposed to combine those of a diuretic, antilithic, aphrodisiac, and emmenagogue, and is by some believed to have a decided power of promoting uterine contraction. its special influence, however, upon the uterus is, to say the least, very doubtful; and the same may be said of any influence it may have been supposed to possess over the sexual propensities. it has been found in the urine after having been swallowed. The probability is that it owes its medical activity to the soda, which is rendered milder both in its local and constitutional effects by its partial neutralization. it may therefore be considered as locally a very gentle irritant, and, when swallowed, somewhat antacid, sedative to the circulation, and probably, like the alkaline carbonates, more or less diuretic. internally it has been used to promote menstruation, to relieve dysmenorrhea, to facilitate labour, and to moderate the sexual passion; but little if any confidence can be placed in it, in reference to these effects, any further than as they may sometimes be indirectly produced by the correction of acid in the system, and a slight reduction of circulatory excitement. The medicine may be used for all the purposes of the alkaline carbonates, in a moderate degree; the neutralization, namely, of acid in the primae viae, the circulation, and the urine, and consequently for the relief of uric acid gravel. The boracic acid, when liberated by the union of the soda with any systemic acid, has itself little effect, probably not more than carbonic acid, and is said to be eliminated with the urine. The dose is from thirty to forty grains.

Borax is used chiefly as a local remedy. it is much employed in the sore-mouth of children, especially that variety of it denominated thrush, the muguet of the French. it is applied either in the form of powder, mixed with from two to eight parts of sugar, and sprinkled on the affected surface, or in that of honey of borax. in solution, it has been used as a lotion in freckles and other discolorations of the skin, ringworm of the scalp, pityriasis versicolor, and ill-conditioned ulcers. For these purposes half a drachm may be dissolved in a fluidounce of rose-water, or other agreeable aromatic water, or, in the case of ringworm of the scalp, as recommended by Dr. Abercrombie, in distilled vinegar. it has also been used, mixed with the white of egg and almond oil, as an application to sore nipples. in fact, borax may be employed, externally as well as internally, for all the purposes of the milder alkaline preparations.

Honey of Borax (Mel Boracis, Br.; Mel Sodae Boratis, U. S.) is made by dissolving a drachm of borax in a troyounce of honey. it is used especially in affections of the mouth, as thrush, aphthous ulcerations, fissured tongue, etc., in which it has the advantage, that the slightly disagreeable taste of the salt is covered by the flavour of the honey.