Note 37 — Prop. IV.—That some few remedial agents act locally on the mucous surface, either before absorption, or without being absorbed at all. That they are chiefly as follow:— (continued 2)

This acid is ascribed by some to Urate of Ammonia, which is to a small extent soluble in water. Others consider that it is due both to this and to Phosphoric acid, which is the opinion of Dr. Prout and Dr. G. Bird. Others attribute it to Lactic acid, which is stated by Berzelius, Lehmann, and Simon, to exist in healthy urine. Some consider the acid to consist in a Super-phosphate of Soda. Liebig supposes that it is due to Uric acid, held in solution by the common Phosphate of Soda. He also considers Hippuric acid to be an invariable ingredient in healthy human urine.