In oxaluria, Dr. Prout long ago recommended hydrochloric acid, and its use is especially indicated for the impaired digestive power, and the anxious and depressed mental condition usually connected with the malady (v. p. 197). It may be given before meals with a bitter, such as nux vomica or chirata, and continued till urates begin to appear in excess in the renal secretion. In cystic oxide and phosphatic deposits with alkaline urine, it is also useful, and has sometimes been injected into the bladder for its local effect (m ij. ad 3 iv. Aq.)