Dilute nitric acid is a serviceable tonic in cases of nerve-debility and of convalescence from acute disease, when appetite and digestive power are impaired. It acts well in combination with a few minims of tincture of nux vomica, stimulating the gastric glands and the biliary secretions, and may be given between meals, or shortly before or after, according to the conditions already mentioned under hydrochloric acid (v. p. 197).