This is procured from bitter almonds. For an account of the process the reader is referred to the U. S. Dispensatory. it is a white, crystallizable substance, inodorous, of a sweetish bitter taste, freely soluble in water and hot alcohol, slightly so in cold alcohol, and insoluble in ether. When mixed with emulsin and water, it is converted into the oil of bitter almonds, altogether identical in properties with that obtained by distilling the fruit. Now, as emulsin is contained in sweet almonds, it follows that a preparation may be made, having the effects of hydrocyanic acid, by rubbing together a little amygdalin, sweet almonds, and water, so as to form an emulsion. Wohler and Liebig recommend that 17 grains of amygdalin should be added to a fluidounce of emulsion of sweet almonds, prepared with two drachms of the fruit. The dose would be from thirty minims to a fluidrachm. As amygdalin keeps well when dry, a preparation of uniform strength could thus be obtained when wanted. Amygdalin itself produces no poisonous effect when swallowed; as there is nothing in the stomach which can act the part of a ferment like emulsin; nevertheless, it should not be swallowed largely, lest by accident something might have been taken having this property.*