When these experiments were begun, April, 1906, there was nothing in the advertising literature on Somnos to indicate whether this article is a solution or a pure substance. On the label on the bottle, in the circular accompanying the bottle, and in the booklet “Somnos,” the word Somnos seemed to be used as a synonym of “Chorethanal alcoholate,” C_{9}H_{11}O_{5}Cl_{9}, and physicians were prescribing and pharmacists dispensing it in the belief that it was a pure substance. “The pure substance; some kind of an alcohol; nothing to do with choral,” was the way the druggist from whom the samples were purchased put it. Thus information absolutely indispensable for any rational comparison of Somnos with other hypnotics was withheld from the physician.[86] [86] Two weeks ago (Journal A. M. A., Sept. 1, 1906, p. 695) it was pointed out that the manufacturers now give this information, but in a wholly unnecessarily obscure form. Hence, before beginning the physiologic experiments it was necessary to determine the strength of the preparation; for this purpose three chlorin determinations (by the Carius method) were made. On the assumption that all the chlorin present was in combination as chloral glycerate, C_{3}H_{5}[CCl_{3}.C(OH)_{2}]_{3} = C_{9}H_{11}O_{6}Cl_{9}, and calculating the percentage of this in Somnos, the following results were obtained: (1) 5.11 per cent.; (2) 5.15 per cent.; (3) 5.10 per cent. Somnos, therefore, was found to contain approximately 5 per cent. of chloral glycerate and its physiologic action was compared with that of a 5 per cent. solution of hydrated chloral. In some experiments the hydrated chloral was dissolved in water; in others, in 10 per cent. alcohol (Somnos was found to contain at this time about this percentage of alcohol); in other experiments glycerin was added, as Somnos was found to contain this substance. No very marked differences were found in the physiologic action of the three solutions. FATAL DOSE OF SOMNOS FOR THE LOWER ANIMALS The booklet on Somnos states that “Somnos has no toxicology”; that while chloral hydrate causes “acute poisoning,” “deep coma,” etc., Somnos is “harmless in twenty times the dose prescribed,” “coma unknown, etc.” The physician would scarcely suspect from such statements that Somnos is as poisonous a substance as solutions containing hydrated chloral in corresponding amount; that such is the case is shown by the following experiments. These experiments were necessarily made on the lower animals. While such results do not enable us to draw very definite conclusions as to the absolute toxicity of poison for man, the results on animals are conclusive as regards the relative toxicity for man of such closely related drugs as hydrated chloral and Somnos.[87] [87] That portion of the report describing the experiments on animals is here omitted. It was printed in full in The Journal and in the Report of the Council on Pharmacy and Chemistry, 1905-1908.