We are only able to learn the action of medicaments by studying the action of poisons, for all medicaments in strong doses are poisonous. Now, to understand a poison thoroughly, we must experiment with it on the animal. Simpson administered chloroform to men only after Flourens had determined its anæsthesic properties on animals. Liebreich, after he discovered chloral, studied its physiological properties on animals, and only after long and learned studies was he able to give it a place in human therapeutics. At the present day, chloral is one of the most extensively used medicines, one which has relieved innumerable patients. When I carried out my research on chloralose, before studying its effects on myself, I began by giving it to cats and fowls. I was ignorant of the degree of toxic power of this new, still unknown substance, and, at the risk of appearing very pusillanimous, I did not wish to begin on myself; I preferred trying it on a fowl. Not that I estimate my life very highly, but after all, however low an estimate I may place on my own life, I think it is worth more than that of a fowl. Many other medicines have been thus experimented with on animals before it was possible to ascertain their effects on man. Kocher discovered cocaine, Knorr antipyrine; and these two admirable medicines did not find their way into therapeutics until their mode of action and their toxic power had been ascertained on animals. In a word, the whole of present-day therapeutics has for foundation, not only ancient clinical observation, which it would be supremely foolish to disdain, but also the experiments of modern times, which it would be equally foolish to proscribe. Perhaps certain people imagine that there are no therapeutics, and that we can replace by auto-suggestion, prayer, or hypnotisation, everything which doctors generally use to cure or allay disease. It is difficult to reply to such objections, because those who make them have never opened a work of science nor seen a patient. They see things as they wish to see them. They imagine that the exterior world is constructed according to their interior vision, and they do not deign to come into contact with reality. They believe that enthusiasm can supply the place of instruction, and that a certain doubtful generosity can replace profound and patient study. They maintain perhaps that chloral does not make one sleep, that salicylate of soda does not alleviate rheumatic pains, that bromide of potassium does not check attacks of epilepsy. Perhaps they will even continue to say so for a long time to come. Let them talk; progress will be made without them. _Les chiens aboient et la caravane passe._ FOOTNOTES: [7] See footnote, p. 17. [8] These statistics can be found in all technical works; and I refer those who may be curious to study them in detail to the special memoirs and excellent treatises on pathology which have been published in England, France, and Germany. See also appendix.