When this disorder is recent, and produced by a decided occasional cause, there may be hopes of a lasting recovery; otherwise it is rarely, if ever, cured. An eruption of the menses, or of the haemorrhoids, during a paroxysm, alleviates it; improper management causes an asthma more readily to end in a dropsy; paroxysms of convulsive asthmas greatly endanger the life at every return, yet seldom prove fatal. If frequent and long continued, should the patient escape with his life, a dropsy is the result, which is his destruction. If a slow fever comes on, an unequal intermittent pulse, a palsy of the arms, a continual palpitation of the heart, a preternatural small discharge by urine, or a syncope, death is at hand; as these symptoms show, that the heart or its connected vessels are organically injured. An asthma affecting old people usually attends them to the grave.

Dr. Cullen observes, "That the asthma depends upon a particular constitution of the lungs: that the proximate cause is a preternatural, and, in some measure, a spasmodic constriction of the muscular fibres of the bronchiae, which not only prevents the dilatation of the branchiae necessary to a free and full inspiration, but gives also a rigidity, which prevents a full and free expiration. This preternatural constriction,"he adds, "like many other spasmodic and convulsive affections, is readily excited by a turgescence of the blood, and other causes of any unusual fulness and distention of the vessels of the lungs."

When this spasm is removed, the patient, after the expectoration of a little phlegm, feels himself almost restored to perfect health; for the cause being obviated, and there being no fixed obstruction in the lungs, the symptoms totally disappear. The proximate cause of theconvulsive asthma, when complicated with the humoral, is a spasmodic contraction of the air vessels of the lungs, occasioned by an increased secretion of mucus, from a relaxation of the mucous glands.

The chief predisposing causes of the convulsive asthma are, a narrow contracted chest, morbid irritability of the lungs, and pulmonary obstructions in consequence of tubercles, either scrofulous or formed by repeated catarrhs, winter coughs, pleurisies, and perip-ncumonics.

The occasional causes of the convulsive asthma are, cold, moisture, sudden changes of weather, dust, metallic fumes, smoke and other particular smells, me-phitic vapours, evacuations, great fatigue, neglect of exercise, shouting, and all strong exertions of the voice, certain disorders in the constitution, anger, joy, surprise, fear, grief, and other depressing passions, excess in venery, and intemperance in diet.

When, however, we compare the action of these remote causes with the spasm supposed to occasion the disease, the connection is not very clear; and, indeed, while anatomy has not ascertained the existence of muscular fibres in the bronchial cells, or the branches of the trachea ultimately terminating in them, it is not easy to admit this cause. There are, indeed, some reasons for supposing the diaphragm alone affected, since respiration is chiefly carried on by its means, and the convulsive asthma is intimately connected with the state of the stomach and bowels. When the diaphragm is affected, by consent of parts usually acting together, the intercostal muscles are also spasmodically contracted. This idea is in some degree supported by the symptoms of pleurisy, where the diaphragm gives little assistance in respiration, as the ribs cannot be raised without pain.

It cannot have escaped the attentive observer, that the remote causes and threatening symptoms of convulsive asthma and gout, are not very dissimilar; the period of attack, the firm health in the intervals, and the subjects most liable to these diseases, are still stronger marks of the connection; but our pathology is in too imperfect a state to explain the reason why a previous debility of the system, followed by irregular action, should, in one case, produce inflammation in the extremities; and in the other, spasm on the organs of respiration. We indeed see, in general, that those subject to asthma have some imperfect conformation of the chest, or some obstruction in the organs which it contains; and we see, also, that an accumulation of mucus in the bronchial glands, or a suppression of the usual discharge, will often bring on fits of true convulsive asthma.

A late author, Dr. Bree, who is himself an asthmatic, has endeavoured to bring us back to the humoral pathology, and to connect more intimately the convulsive and humoral asthma, though not with signal success. His chief argument consists in the appearances after death: but we have already remarked, that these are effects only; and in general the quantity discharged at the termination of a fit is so inconsiderable, the relief is so often obtained previous to the discharge, and the marks of accumulation even when present are so trifling, that this opinion cannot be supported.

The hopes of relief are to be estimated from the violence and duration of the symptoms, the age of the patient, the condition of his constitution, the nature of the predisposition, and the power of the exciting-causes. If the symptoms of the spasmodic affection in the lungs run high; if the disorder be of long standing, and, when once excited, continues for several days; if the returns of it be frequent; if the lungs be greatly obstructed with phlegm' at the termination of the convulsive fits, and an obstinate cough remains during the intervals, with a laborious respiration, and a copious expectoration of mucous matter; the cure is difficult, tedious, and uncertain. Tubercles and obstruction in the lungs are symptoms too unfavourable to admit of hope. If, on the contrary, the disorder be recent; if the patient's constitution be not greatly impaired; if there be no natural deformity in the chest; if respiration after the termination of the fit be free, and the cough, with expectoration of phlegm, not violent nor obstinate in its duration; if the occupation of the person be not injurious to the lungs, or, if so, can be easily relinquished; and if the lungs be not obstructed with tubercles, either in consequence of a scrofulous habit, or repeated inflammatory affections, the case bears a favourable aspect, and may, in all human probability, be frequently treated with success. When infants are seized with the asthma, it often ends fatally, especially if powerful means for the removal of it be not applied at its commencement.