Some years since I had occasion to examine the history of admissions to the Retreat, which at that time amounted to more than five thousand cases, and it was found that in more than one tenth of these cases the cause of insanity had been traced to the use of alcohol. This, however, did not embrace those cases which had inherited an unstable condition of brain in consequence of the use of alcohol by parents, and became insane for this reason. Of the sixteen hundred insane and imbecile or feeble-minded persons in Connecticut at the present time, it is estimated that not less than one fifth have become so either directly or indirectly through the influence of alcohol. Some writers estimate the amount of insanity which is caused through the influence of alcohol, on parents and their children, in England, at a much higher proportion, than this. Statistics indicate that a considerably larger amount of spirits, beer, and wine, per capita, is used yearly in Great Britain than in the United States. My present purpose, however, is to draw attention to the part it plays, more particularly when used not immoderately as a beverage (if any use of it as such can be so characterized), in creating a diathesis which renders the brain liable to unstable and irregular action. And I may remark at the outset that it does not so much signify in what form of beverage it may be used. The _quantity_ taken is the important point--whether it be in the form of beer or wine, brandy or whiskey. The alcohol contained in any or all of these articles is _the_ thing sought for, and _its_ influence upon the brain is that of paramount importance and consideration. In order that we may more clearly understand the manner in which the use of alcohol, in its various forms, as a beverage, tends to create an unstable condition of the nervous system and irregular mental activity, it becomes necessary to study, in some measure, its physiological effects upon the system, as they have been demonstrated by means of experiments conducted with scientific accuracy. This becomes the more necessary, as there has always existed, and still exists, in the public mind a firm belief that its effects are quite harmless, and may be even beneficial, _if it is used in moderation only_.