Contraction. - Bor.

Present name. - Sodic Biborate, Acid Borate of Sodium. Na2O2B2O3, 10H1O.

It is usually made by purifying the native salt Tincal by repeated crystallization.

Characters and Tests. - In transparent colourless crystals, sometimes slightly effloresced, with a weak alkaline reaction; insoluble in rectified spirit, soluble in water. A hot saturated solution, when acidulated with any of the mineral acids, lets fall, as it cools, a scaly, crystalline deposit (Boracic Acid), the solution of which in spirit burns with a green flame. 191 grains dissolved in 10 fluid ounces of distilled water require for saturation 1,000 grain measures of the volumetric solution of Oxalic Acid.

Preparation. - Trituration for lx; solution in distilled water for 1 and 3x; dilute alcohol for 2; rectified spirit for 3 and upwards.

Proper forms for dispensing. - lx, Trituration only. 1 to 5x, Solution only. 3 and upwards, Tincture, Pilules, or Globules.