with alcohol—­this medicated blood will exert its greatest chemical effect where the tension—­the pressure—­is greatest, that is, in the cerebro-spinal canal.  The reason for this is found in the fact that endosmosis is most pronounced where the blood pressure is greatest.  This explanation of why the effects of alcohol are enhanced by exposing the individual who has taken it to the effects of a condensed atmosphere will, I believe, appeal to the physiological conceptions of most medical men.  It was the above course of reasoning which, at this stage of the argument, led me to the idea that, just as the effects of stimulating substances are enhanced by exposing the subject to the influence of compressed air, so, inversely, sedatives and analgesics, when brought in solution into the blood stream, either hypodermically or by the stomach, might be greatly enhanced in effect by causing the subject to remain, while under their influence, in a condensed atmosphere.

When I came to investigate the validity of these predictions, as I did shortly after the introduction of antipyrin, phenacetin, and the other members of the same group of compounds, I found my predictions verified, and, indeed, exceeded.  To summarize the whole matter, I ascertained that not only could therapeutic effects be obtained from much smaller doses by exposing the subject to the influence of a condensed atmosphere, but, what was of equal interest, I found that the analgesic influence of the remedies was much more permanent, was prolonged, in short, by this mode of administration.  When we consider how great must be the nutritive changes in the nervous system, and especially in the cerebro-spinal axis, consequent upon increasing the blood pressure in this way, I hardly think that these things should be matters of astonishment.

CONCERNING THE PRACTICAL APPLICATION OF THE FOREGOING FACTS.—­Truths like the foregoing possess, however, much more than a theoretical interest, and we should be greatly lacking in perspicuity did we not seek to derive from them something further than a foundation for mere speculation.  Indeed, the whole tenor of these facts is opposed to such a course, for, view them as we may, the thought inevitably arises that here are things which contain the germ of some practical acquisition.  This, at least, is the impression which they engendered in my own mind—­an impression which, being unable to rid myself of, I have allowed to fructify.  Nor has regret followed this tenacity of purpose, since, by the combination of the three principles previously enunciated, I have been able to devise a procedure which, in my hands, has yielded flattering results in the treatment of a wide range of nervous affections, and notably so in melancholia, chorea, insomnia, neurasthenia, and painful conditions of various kinds.

RECAPITULATION OF ARGUMENT.—­The method in question consists, then, in the combination of the three facts already elucidated.  To recapitulate, they are: