An obstruction connected with the bowels has been a very general cause of this complaint, we mean the suppression of the haemorrhoidal discharge. In the whole circle of practical medicine, we know no question so intricate and difficultly explained as the connection of the haemorrhoidal discharge with the general health; or rather, perhaps, the supposed connection, as stated by the German physicians, We have not found, from our own observation, this connection; but the experience of ages must not be overlooked, or contemptuously disregarded. The haemorrhoids were considered, at a certain period of life, as essential to the male, as the cata-menia to the female, health: their appearance was hailed as a salutary omen, their disappearance dreaded as a dangerous symptom. To this subject we must return: we can only now say, that we have not found this discharge necessary, except when established as an habitual one. We have found its repulsion injurious, and indeed so is that of every habitual discharge. Yet there is evidently some connection between the state of the rectum and the general health; for the fistula, or an abscess in ano, often relieves hectic symptoms; and, to check or stop the discharge, is often injurious, and generally fatal. It was supposed, that as the veins of the abdomen centered in the vena portae, the depletion of these would lessen an obstructed circulation in the liver. But the haemorrhoidal veins do not form a part of the vena portae, and this system is of course untenable. The inconvenience that arises, must consequently be attributed to the suppression of an evacuation, and particularly to that of a discharge, which increases the circulation in the descending aorta. The consequence, as we have already shown, must be a greater determination to the ascending.

Another defect constantly attended with headach is that of the catamenia, whether they have not appeared. or been suppressed. The chlorosis we shall soon notice, but it must be under the disadvantage of not having considered the cause of menstruation. We should have explained this subject under catamenia but were unwilling to disturb the former arrangement too rashly, as it involved such numerous references. If plethora or spasm obstruct the menses, the disease of the head is obviously accounted for: if weakness or inanition render this discharge insufficient, the effect is not so easily explained. The complaint is, however, attended with general debility; every discharge is equally suppressed, and an irregular balance of the circulation is the consequence. With the greatest weakness, with a complexion which shows that the red globules, that index of tone and general health, are deficient, the head is loaded, and haemorrhages from the nose are not uncommon. A similar complaint with headach often occurs in boys about the age of puberty. In these diseases, active cathartics, particularly those whose activity-is exerted on the rectum, are the chief remedies, though in chlorosis, tonics must be also employed.

Repelled fluids from the surface produce very constantly symptomatic cephalalgia. The simplest case of this kind is coldness of the feet; but damp cold weather, with an easterly wind, will in many constitutions bring it on. Partial colds produce rather fever or rheumatism; but in both the head is usually affected. A more severe cause of this kind is the repulsion of acrid matter from the surface, by the application of astringent washes to herpes, or tetter; by saturnine or mercurial applications as cosmetics: from these the head generally suffers, though the mischief is often more extensive, and apoplexy, cachexy, slow fever or epilepsies, are frequent consequences. Repelled gout is a still more serious cause. See Arthritis.

There are causes of headach that act more mechanically. Whatever, for instance, retards the current of the blood in the sinuses of the brain, or the veins which convey the blood from the head, will produce it. Of this kind are various tumours, particularly of the conglobate glands, polypi, exostosis, etc. Whatever prevents the free evacuation of the right auricle and ventricle, contributes to retard the motion of the blood in the veins, which discharge their contents on this side of the heart. More externally, rheumatic pains in the muscles of the head sometimes resemble so strikingly cephalalgia as to be mistaken for it.

We have not mentioned the mental causes, anxiety, fear, suspense, and grief; for these seldom produce the complaint until the body or, in general, the stomach is affected. The cephalalgia of students is often a nervous affection merely. Whatever be the action of the nervous fibres in intellectual operations, its excess is often a cause of pain; though, in many instances, the cephalalgia of students is connected with obstructions of the bowels, and very often with increased determination to the head. The hysteric cephalalgia partakes of this nervous cause, particularly when the pain feels as if a nail was fixed in the brain, from hence called the clavus hystericus. But to this subject we must return when we treat of hysteria.

Authors have endeavoured to distinguish by the particular kinds of pain which of these causes may have produced it, but language fails in describing the different feelings, and their variety. An external soreness, points out an external cause; and, when the remote causes are attended to, we may, with little difficulty, ascertain the real nature of the complaint, and the practice will, of course, be obvious. Where the causes are beyond our reach, the disease may be mitigated, by attending to the directions given for relieving idiopathic headach.

Though the cure of these species of headachs depends on their causes, and we have given, in general, the outline, which will be filled up in treating of the diseases themselves, we may here add a few of the remedies which give immediate relief. One of these is bathing the feet in tepid water, rubbing them with flour of mustard, and keeping up a general circulation to the surface by flannel next to the skin. The effects of a blister we have already mentioned; but the aqua ammoniae, or ether, applied to the nostrils or the forehead by the palm of the hand, often produce instantaneous relief, which authors have explained in the following manner: