(From Haemorrhagia 4050 blood, and to flow). Haematochysi, and sanguifluxus. Haemorrhages, though frequent diseases, are not among the most dangerous complaints to which the human body is subject, and are of importance only in their consequences; for a haemorrhage, when in excess, occasions faintness, and, during the deliquium, the bleeding stops.

The first distinction of haemorrhages is into active and passive. Dr. Cullen, limited by his system, has chiefly noticed the former; but the line is not, as we shall soon find, easily drawn, or fixed with accuracy. Active haemorrhages are those attended with fever, which seem to depend for their existence on coldness and shivering, with the usual attendants, a quick pulse, and marks of a particular determination to the part from which the discharge will proceed. But"degree does not change even a species," according to the canon of the systematics; and often in the lowest state of debility, the legs are cold, the part affected peculiarly hot, and the pulse throbs with vehemence. If such haemorrhages are active, they have no place in Dr. Cullen's system. As a general outline, the distinction will, however, hold with sufficient accuracy, and we shall soon pursue it.

Another distinction is into accidental, and vicarious or critical haemorrhages. The first are only to be styled diseases. When any discharge has been suppressed, blood is often poured from other vessels without any injury, except perhaps when the delicate organization of the brain is injured by it. Vicarious bleedings from the lungs are seldom dangerous; and from the stomach and intestines are only for a time inconvenient. But in the brain we cannot always limit the new discharge so as to prevent injury from compression, though in many cases the blood has been absorbed without any permanent disease. Critical discharges also in the brain are dangerous; nor is it impossible that these or vicarious bleedings in the lungs, if violent, may not occasion at once suffocation.

Active haemorrhages we must then consider as febrile diseases of an inflammatory kind. They are defined by Dr. Cullen pyrexia, with an effusion of blood, independent of external violence; and the blood drawn having an inflammatory appearance. Active haemorrhages chiefly occur in full plethoric habits, most frequently in the spring and in the early months of summer, before the warmth of the air has relaxed the external vessels. Previous to the fever which ushers in the discharge, some general fulness and uneasiness are felt, with a load on the parts from whence the haemorrhage will flow. The topical heat, swelling, or itching, is sometimes considerable. A short rigor which follows is relieved by the usual heat, and the haemorrhage soon comes on during this hot fit. After some time the discharge and the fever both cease; but every spontaneous haemorrhage has a tendency to recur, and if this recurrence happens more than one, after a stated time, a habit is formed which is with difficulty overcome. These very marked appearances do not always occur; but traces of these symptoms may be often distinguished even in the most debilitated states.

The remote causes of haemorrhages are not always those of plethora. The most plethoric states in a robust constitution are not peculiarly attended with these discharges; and, on the contrary, extenuated habits are occasionally subject to them. The principal remote causes of active haemorrhages are, an alteration in the balance of the circulation, or a want of energy to propel the fluids to the surface. The immediate cause is the increased impetus of the blood in the hot fit, which is produced by the distended vessels, and the effort excited to conquer the resistance. The vessel ruptured is in general one constitutionally weaker than any other.

Persons subject to haemorrhage are usually those of an irritable, delicate constitution, sometimes the weak and exhausted. Violent exertions, at particular periods of life, will occasion them in every habit. Haemorrhages are in general most violent in the full and strong; but more permanent in the weak and irritable. The reason is, that in such cases the red globules and the gluten are chiefly discharged, on which the strength greatly depends. Fainting therefore soon comes on, from the depletion of the arteries. In the weak the lesser vessels yield, and a less proportion of these parts of the blood is discharged. The evacuation contains chiefly the serum coloured only with the red globules. This is in a great measure the case where the haemorrhage depends on a want of energy in the arterial system to propel the fluids to the surface; and the attendants are surprised to find that such considerable discharges can be borne, when in reality a very small portion consists of the nutritious fluids.

The repetition of haemorrhages is connected with the causes producing an irregularity in the balance of the circulation, generally arisingfrom the predominating energy of some particular part of the arterial system. The plethora soon returns, for generally the appetite is more keen; the digestive and assimilatory functions

H AE M 728 H AE M always proceed with augmented vigour, while the secretions are for a time retained. The quantity is in this way soon restored, but the quality is gradually deteriorated. The fluids are thinner; for though water can be easily supplied, the formation of the red globules, of the gluten, and the fibrin, is not the work of a short period, and it proceeds slowly in proportion to the debility induced. The progressive fulness of the vessels of different organs, at different periods of life, we have already explained, and of course the successive discharges from the nose, lungs, and liver, haemorrhoidal and urinary vessels. We may resume the subject, at some length, under the article Haemorrhoides.