Prep. Made by dissolving fifty grains of boracic acid (Bo3 + 3 HO) in one fluid ounce of rectified spirit.

Use. It is used in the Pharmacopoeia to test the presence of turmeric in rhubarb. Turmeric becomes of a red colour when treated with the solution of boracic acid, whereas the colouring matter of rhubarb is unaffected by this reagent.