We shall mention haemicrania as an idiopathic pain of the head, though by some authors it is referred to intermittents; by others to rheumatism. We mean to treat of it, however, more particularly under its own appellation.

On a review of these causes of idiopathic headach, we must regret that the source of so few cases is discoverable, and that we have scarcely appropriate remedies for any of those which we can ascertain. In general, in every instance, the necessity for keeping the bowels free, must be obvious from what we have said under the article of Cathartics. A drain also from the head, by a perpetual blister on the vertex, to the bone of the neck, or behind the ears, must be equally so. Avoiding accumulations and flatulencies in the stomach, for the reasons formerly assigned (see Cathartics), must be advantageous. Emetics are often advised for this purpose; but they are doubtful remedies, as they determine so powerfully during their action to the head. Yet we suspect that they are not injurious, since their inconvenience is transitory, and their beneficial effects durable; and we shall find them peculiarly useful in symptomatic headachs. As a remedy for flatulence, the fetid gums will probably be useful, even in idiopathic cephalalgia; and, if joined with aloes, will be more serviceable. From the effects of camphor in fevers, we suspect that it may be useful in headach; and with nitre we have often employed it with advantage. It is a too common practice to cut off the hair, partly because it is supposed to keep the head warm, and partly that cold applications may bo more conveniently employed. This practice has not, how ever, the sanction of long experience; nor is it supported by reason. Each hair is a vegetable, nourished by a bulbous root, supplied by numerous blood vessels. These, though small, from their number 3 D 2 convey no inconsiderable quantity of fluids; and as the external and internal carotids arise from a common trunk and anastomose in some of their branches, whatever cause increases the circulation in the former must lessen it in the latter. The author of this article suffered for many years an irregularly returning paroxysm of headach, for which he could assign no cause; but at last discovered that it frequently returned after shaving the head. He suffered his hair to grow, and from that time it gradually lessened in violence, in duration, and the frequency of its return. From being a complaint highly serious, and beginning to affect the memory, its returns are now rare, and never so violent as to unfit him for any exertion of body or mind.

Among the means of lessening the force of the circulation in the head,wc should, perhaps, have mentioned more early, the use of slight occasional bleedings; the application of leeches or cupping glasses. They are all occasionally useful. In such cases, too, the temporal artery has been sometimes opened with the best effect.

The diet in those subject to headach should be light, cooling, and moderate in quantity: the usual drink, water, with a moderate quantity of the wine most suitable to the constitution. The white wine is generally preferable. The mind should be kept calm; all the more violent exciting passions avoided; the exercise moderate, and never in the heat of a summer day, or under a warm sun. The apartment should be large; the sleeping room lofty and well ventilated; the head raised high on the pillow. In short, every thing that accelerates the circulation, or determines the blood to the head, should be carefully avoided.

Symptomatic headach is a disease of so many organs, that it is impossible to "fix the variable Proteus by any chain."headach attends fevers of almost every kind; and, when the infinite variety of forms of fevers are considered, so many must there be of cephalalgia, as a symptom of this complaint only. Every obstruction in the bowels, every accumulation of sordes, or indigestible matter in the stomach, produces the same disease: every obstruction to the regular evacuation of any gland, particularly those of the surface, has a similar consequence; every nervous affection, either from excessive excitability or exhaustion. Are we then to be surprised at its frequent occurrence? Is it not wonderful that the head is ever free from pain ? But to be more particular.

The sympathy between the head and stomach has been so generally observed, it is the subject of such constant experience, that to enlarge on it would be superfluous. We have already observed how difficult it is to ascertain the organ primarily affected. The apprehension of increasing any effusion in the brain, has made the distinction an object of peculiar anxiety; but we are confident in saying, that, in the doubtful cases, no hazard attends the exhibition of an emetic: we must repeat, the inconvenience is temporary, the advantages durable. We urge this with more force, as, with the experience of near forty years, we find the decision difficult and precarious: the tyro, without a suspicion of the difficulty, by the exhibition of an emetic has succeeded. If to this we add that headach is one of the first symptoms of fever, this plan has additional recommendation. It must be followed by a cathartic; and, unless great weakness forbid, this cathartic must be an active one: the foundation of its use has been already explained. In this way headach, whether idiopathic or symptomatic, will be usually relieved. If relieved only, and congestion in the head is obvious from heavy or inflamed eyes, languor and listlessness, a blister is no equivocal remedy, whatever may be the cause.

Headach, if a symptom of slow or obstructed bowels, is to be relieved in the same way by an emetic and laxative, but chiefly by the latter; and, in these circumstances, a moderate discharge, steadily continued, is more useful than temporary active purging. Eccopro-tics are chiefly useful; and they should be long persisted in. The choice of the medicine must be determined by the causes. If the fault be in the biliary secretion, the purging mineral waters, soap, sometimes assisted by rhubarb, or neutral salts with the occasional use of calomel, will be useful. If a torpor of the intestines occasion the disease, the rhubarb, the aloes, and even the colocynth, will be necessary, as less active medicines will have little effect; if mucus involving worms, calomel, rhubarb, resin of jalap, and even gutta gamba. We doubt, however, whether worms be so frequent a cause of headach as has been supposed. The hydrocephalus was not long since styled a worm fever; and the early symptoms of irritation, accompanied by pain in the head, were attributed to these animals. Yet, as all accumulations in the bowels may occasion headach, those from worms must not be hastily rejected.