c. Saffron, 15 grains; boiling water, 2 oz.; infuse and strain. Add tincture of rhubarb 11⁄2 oz.; concentrated infusion of rhubarb, to make up to 4 oz.
BORACIC ACID (-răs′-). H3BO3. Syn. Boric acid, Sedative salt†, S. s. of vit′riol†; Acidum boracicum (-răs′-), L.; Acide boracique, A. borique, Fr.; Boraxsäure, &c., Ger. The pure acid is obtained from common borax. That of commerce is extracted from the boracic acid lagoons of Tuscany.
Prep. 1. Borax, 1 part; boiling water, 4 parts; dissolve, and add sulphuric acid until the solution acquires a distinctly acid reaction, for which purpose about 1⁄2 the weight of the borax will be required. As the solution cools, crystals of BORACIC ACID will be deposited. These may be purified by placing them on a filter, and washing them with a little very cold water, followed by re-solution, in boiling water, and recrystallisation. Nearly pure.
2. As the last, but substituting hydrochloric acid for the sulphuric acid, there ordered. Very nearly pure.
3. By exposing the product of the first crystallisation of either of the preceding formulæ to heat in a platinum crucible, and redissolving and recrystallising the residuum. Chemically pure. Used in analysis.
Prop., &c. Odourless; bitter-tasted; dissolves in 25 times its weight of cold water, and in 3 times its weight of boiling water; very soluble in alcohol, which then burns with a bright green flame; reddens litmus; browns turmeric-paper (properties characteristic of this substance); when strongly heated it forms a brittle glass (VITRIFIED BORACIC ACID) on cooling. The crystallised acid contains 3 atoms, or 43·5% of water. Its salts are called BO′′RATES.
Uses. Boracic acid was once administered internally, in large doses, as an anodyne, antispasmodic, and sedative, but is now scarcely ever employed as a medicine. The crude acid is used in the manufacture of borax; the pure acid in the manufacture of certain chemicals.
Boracic acid is extensively used in Sweden and other countries for the preservation of milk. Meat which has been soaked in a solution of the acid for a few seconds, and milk to which a small quantity has been added, will keep much longer than they would otherwise do. In Sweden alone boracic acid to the amount of 75,000l. was consumed in one year. It is said to be a perfectly harmless antiseptic.
BORACIC ANHYDRIDE. See Boric Anhydride.
BORATE. [Eng., Fr.] Syn. Bo′′ras, L.; Boraxsäure salze, Ger. A salt in which the hydrogen of boracic acid is replaced by a basic radical. The borates may be formed by either digesting the hydrate of the base in a