Numerous experiments have been made with a view to elucidate the physiological effects of alcohol. As regards the human subject, however, inherent difficulties of strict experimentation, and perhaps still more the difficulties of correctly interpreting the results, have made it desirable to exercise more than ordinary caution before accepting, as definitely established, many of the conclusions arrived at.

Particularly is this the case in regard to the effects produced by alcohol on the mental processes and the nervous functions. These processes and functions are admittedly very complex. The human subject of the experiment may himself be biassed as to the expected results, and that bias, in some experiments, may to some extent affect the results. His own estimate of his performances under the influence of alcohol is affected by that influence itself. He can scarcely be prevented from knowing when alcohol is given to him, so that it is difficult to obtain him strictly "neutral." And no doubt also preconceived ideas, in this sphere just as in others, may sometimes unconsciously affect the judgment of the experimenter, however impartial he may desire to be.

Bearing these facts in mind, a careful review of present knowledge respecting the action of alcohol on the human organism has been prepared by an influential committee of medical men for the Central Control Board (Liquor Traffic) of the United Kingdom.1 In compiling the following account, this review has been freely drawn upon, since it is the most authoritative summary available of modern scientific views on the subject.