Acidum Phosphoricum Dilutum (U. S. P. l0%). Tonic and refrigerant; stimulates the nutrition of the nerve tissues, eliminates insoluble phosphates, and stimulates the sexual function. Dose, 20 to 60 I. In small doses (5 to 10 I), combined with a bitter tonic, this agent serves very well in the subjective and often imaginary pain and distress of depressed and irritable persons verging upon hysterical manifestations of the quiet, stubborn type. In small doses it is a valuable tonic to rapidly growing young people under the mental stress of school and college work and in the debility following acute disease. Some homeopathic surgeons assert that very small doses will relieve the peculiar neurosis in the stump sometimes following amputation.