The cure of asthma must differ according to its nature, and the periods in which the remedies are employed. The only disease properly distinguished by this appellation is the convulsive asthma; but the humoral asthma is so often connected with it, at least as an exciting cause, that we shall consider it in this place.

The treatment of convulsive asthma must differ, when considered with a view of removing the fit, or of preventing its recurrence. It was formerly a constant practice, in every case of difficult breathing, to bleed; and bleeding has been repeatedly employed to mitigate the urgent,symptoms of the moment. We have great reason to think that this practice has been highly injurious; and repeated bleedings in repeated fits have undoubtedly hastened the common termination of asthma, the dropsy. Yet so sudden is frequently the relief, that patients once accustomed to it are displeased if so ready a remedy is omitted, and it is often necessary to take a small quantity of blood to satisfy their minds: indeed it frequently happens that a slight bleeding will be equally useful with a large one. Such is the connection established in the human system by concomitant effects, that we are told by Dr. Whytt, that a nervous paroxysm has been removed by the momentary puncture of the arm.

Vomits are considered by Dr. Akenside as highly useful in shortening the paroxysm, and he recommends them to be given early, indeed almost in the moment of the attack. We own that we have followed this practice with some hesitation, yet we have never found it inconvenient or dangerous. Physicians have usually waited till some expectoration has come on, but the remedy is then unnecessary. Dr. Akenside gave very small doses of ipecacuanha only; and remarks, that it is equally useful when it nauseates, as when it vomits. The more rapid effects of the white vitriol have not, we believe, been tried, though they may probably unite a tonic power with the usual effects of vomiting.

Blisters require too long a period for their operation to be of great service during the fit; but, when the paroxysm is unusually protracted, they may be of service.

The chief benefit to be expected during the attack is from the volatile antispasmodics; and, as no inconvenience is likely to follow, expectorants have been combined with them. With the mixtura camphorata, have been united aether, aqua ammonias, tinctura foetida, lac ammoniac, and even opium. The quickest and most diffusive stimulants are undoubtedly the best; and these mentioned may be combined in any proportion the physician may prefer. Opium is however a medicine of equivocal utility. It is mentioned because it has been recommended; but in our hands it has been rather injurious than useful. Mixing the opium with squills, or any active expectorant, or with gentle laxatives, to avoid its constipating effects, are proper precautions.

Bathing the feet in warm water has been sometimes useful; and in the very violent attacks, cataplasms, with garlic applied to the feet, have been of service. When a fit of true convulsive asthma is apparently connected with water in the chest, an active laxative has given great relief. In such cases, ten grains of jalap, with as much calomel, have been given with advantage.

The intervals between the Jits are the periods when medicine may be most usefully employed; for though we lessen debility, and prevent in some degree any organic derangement by shortening and mitigating the fit, yet it scarcely ever happens that a paroxysm proves fatal.

The diet should, in general, be light and digestible; and every thing acescent and flatulent should be avoided. As life advances it should be more generous; and Madeira, or Port, if it does not produce acidity, may be taken with freedom, regulated by former habits. The less perfectly fermented ale is injurious, but porter is an excellent liquor with the meals; and, if not too flatulent or too strong, agrees well with asthmatics. In some cases of asthma however these liquors are too stimulant; and water, or a solution of cream of tartar in water, is found more useful. Though acescents are injurious, the acids less susceptible of further change, as vinegar, or the pure acid of tartar, are supposed to be very beneficial. Tea should be avoided; but coffee is supposed to be highly useful: and the warmer plants of our own country, as peppermint, rosemary, and pennyroyal, may with advantage supersede those of foreign growth. Supper should always be light of digestion, and not flatulent or acescent. The ship biscuits, with porter, or brandy and water not sweetened, or some beef tea, will fully supply this meal.

The situation of asthmatic patients is of great importance. In general, they cannot breathe with ease in an elevated spot; and too great a proportion of oxygen in the air, irritates their weak and susceptible lungs. In what the lower quality of the air consistent with their case, consists, we know not. It has been suspected to be azote or hydrogen; but, from a fact mentioned by Dr. Percival, that the asthmatics who have been disordered by the fumes of lead, find relief from working in the lime kilns, it may be fixed air, which, from its greater specific gravity, falls into the lower strata of the atmosphere. Whatever may be the cause, the fact is well established. Asthmatics do not always find great advantage from a warmer climate. Such however is the variable nature of this disease, that some cannot breathe but in a less inclement atmosphere than this country affords.

The other physical qualities of the air are probably of importance. A due degree of elasticity is apparently necessary; but this, too, may be in excess, and produce inconvenience. An easterly wind is always injurious; but to what all the disadvantages of this peculiar state of the air may be attributed, we are yet ignorant.

The exercise should be steady and regular. Walking, for the reasons formerly assigned, is the most salutary; and sailing, for a similar reason, has been found very advantageous. If exercise on horseback or in a carriage is necessary, the feet must be well covered to keep up an equable, steady perspiration. Moisture should be carefully avoided; and, if accidentally wetted, the clothes should be immediately changed. The cold damp air of the night should be shunned with equal anxiety. Flannel should be usually worn next the skin in winter, and a moderately thick calico in summer.