Diarrhoea very often proves a natural cure of insanity; at least there is every reason to suppose that such evacuation has frequently very much contributed to it. The number of cases which might be adduced in confirmation of this observation is considerable, and the speedy convalescence after such evacuation is still more remarkable. In many cases of insanity there prevails a great degree of insensibility, so that patients have appeared hardly to feel the passing of setons, the application of blisters, or the operation of cupping. On many occasions I have known the urine retained for a considerable time, without the patient complaining of any pain, though it is well known that there is no affection more distressing than distention of the bladder. Of this general insensibility the intestinal canal may be supposed to partake: but this is not commonly the case, and if it should, would be widely different from a particular and exclusive torpor of the primæ viæ. There are some circumstances unconnected with disease of mind, which might dispose insane persons to costiveness. I now speak of such as are confined, and who come more directly under our observation. When they are mischievously disposed, they require a greater degree of restraint, and are consequently deprived of that air and exercise, which so much contributes to regularity of bowels. It is well known, that those who have been in the habits of free living, and who come suddenly to a more spare diet, are very much disposed to costiveness. But to adduce the fairest proof of what has been advanced, I can truly state, that incurable patients, who have for many years been confined in the house, are subject to no inconveniences from constipation. Many patients are averse to food, and where little is taken in, the egesta must be inconsiderable. To return from this degression: it is concluded, from very ample experience, that cathartic medicines are of the greatest service, and ought to be considered as an indispensable remedy in cases of insanity. The good sense and experience of every practitioner must direct him as to the dose, and frequency, with which these remedies are to be employed, and of the occasions where they would be prejudicial. VOMITING.--However strongly this practice may have been recommended, and how much soever it may at present prevail, I am sorry that it is not in my power to speak of it favourably. In many instances, and in some where blood-letting has been previously employed, paralytic affections have within a few hours supervened on the exhibition of an emetic, more especially where the patient has been of a full habit, and has had the appearance of an increased determination to the head.