I administered the whisky upon the same principle that governs us when we apply stimulating lotions to an inflamed eye, or give alcoholic liquors in passive congestions of other parts of the body. The warm bath was prescribed with a view to its dilating action upon the blood-vessels exposed to its influence; and the sitting position with the object of facilitating the flow of blood from the head, and impeding its return through the carotids and vertebrals. All these measures I had employed previously with success, in many cases of inability to sleep due to delirium tremens, and which is almost always of the passive or asthenic form. In the instance under consideration their action was all that could be desired. At ten o’clock, having taken the whisky and bath as directed, she sat down to sleep in a comfortable chair, and, as her mother informed me, was asleep in less than half an hour. She awoke about three o’clock, but soon fell asleep again after another dose of whisky, and remained in this condition till about nine o’clock in the morning. She then took breakfast, feeling very much refreshed, but was unable to remain awake longer than two or three hours, but, taking to her chair, slept soundly till evening. That night she was again overcome with sleep, and it was passed very much as was the previous one. No further medicine was required, and after a few nights she went to bed as had been her custom, and slept soundly till morning. Under the use of iron and lager beer she recovered her health and strength. The foregoing cases are given as examples of the two forms of morbid wakefulness or insomnia to which I wish to call attention. They show that, though the cause in each variety may be essentially the same, the means of relief are not altogether identical. It is important, therefore, to discriminate between them. But the main point upon which it is necessary to insist is, that in morbid wakefulness, whether occurring in strong or weak persons, there is always an excessive amount of blood circulating through the substance of the brain. In the course of the discussion of the points involved in the physiology of sleep, this subject was incidentally noticed. In the following chapter, however, it will be dwelt upon with more particularity. CHAPTER IX. THE EXCITING CAUSES OF WAKEFULNESS. Every cause capable of increasing the amount of blood ordinarily circulating through the brain may give rise to wakefulness. As these causes are more or less under the control of the individual, it is important that they should be fully considered. An increased amount of blood is attracted to the brain, and wakefulness is produced: