Hedonal is one of the newer products of the urethane group, it being combined with higher alcohols than the other members. It is a white crystalline powder with an aromatic odour and taste. Slightly soluble in water, it is readily soluble in any organic fluid. It is said to be fully oxidised in the system. Given in doses of ½ to 2 grms. (7 to 30 grains) it has a sedative action on all nerve-cells. It has little effect on the temperature, lowering it only about ·3°.; the pulse is lowered from six to twelve pulsations per minute; the blood-pressure decreases by from 10 to 15 mm. of mercury—evidently a vaso-dilator effect. There is a notable increase in the total quantity of urine excreted, but without increase of the total solids. In nervous insomnia it produces sleep, generally of some hours' duration, in from half to two hours, without dreaming or bad after-effects. It proved of value in a case with gastric crises. Excellent calmative results were obtained in the excited state of melancholia and of folie circulaire. It has no effect in reducing the number of fits in cases of epilepsy, but is of value in the excited stage following them. In many cases it succeeds when sulphonal, trional, chloral, and even morphia are only partially successful.