glutamic acid

Chemistry: Glutamic acid, amido-glutaric acid CH(NH2)COOH. Obtained C5H(NH2)O4, or CH2CH2COOH. by boiling vegetable gluten with dilute sulphuric acid, or casein with hydrochloric acid and stannous chloride. It is best prepared by boiling the gluten with 82 per cent. alcohol, which extracts the mucin, and boiling for twenty-four hours, with an inverted condenser, one part of the mucin with three parts of sulphuric acid and six parts of water; it is then filtered, saturated with chalk, filtered and evaporated to one-third of its bulk; the calcium salt is decomposed by oxalic acid, the exce of oxalic acid is removed by carbonate of lead, and the exce of PbCO3 by HS gas, and, the filtrate evaporated, tyros in crystallizes out, and afterward the glutamic acid, which crystallizes out of hot water in tetrahedral crystals, which are nearly insoluble in alcohol and in ether, melt with partial decomposition at 140°. Glutamic acid forms crystalline compounds with acids, and also forms salts. The barium salt gives characteristic needle groups like Wawellite.