By the term alcohol, as before stated, the U. S. Pharmacopoeia recognizes a spirit of the sp. gr 0.835, prepared by distilling brandy or other form of ardent spirit. The corresponding British "rectified spirit" has the sp. gr. 0.838. Officinal alcohol is never used internally; but externally it may be employed as an evaporating lotion, applied on a single thickness of linen, so as to admit of free evaporation. By its chemical influence in the abstraction of water, it is thought to produce the shrinking of blood-vessels; and, when brought into contact with the blood, causes its coagulation. Hence it has been recommended for the suppression of hemorrhage by direct application to the bleeding vessels. But its chief value is as a chemical and pharmaceutical agent. From its solvent and preservative properties, it answers an excellent purpose for preparing tinctures of substances wholly insoluble in water. (See first part of this work, page 61).