Under circumstances like these, death reveals the operation of a wise and beneficent law. Man, in the pride of his ignorance, may regard the result as a great evil, and to him it truly is such; but a little reflection will show, that it is the unavoidable result of a law designed to prevent evils still greater. Among other provisions intended for the preservation of every existing species, it has been ordained, that, when placed under certain conditions, some shall die that others may live. When a class of animals become so excessively numerous that something essential to its existence, such as air, food, or water, is in danger of being exhausted, a disease quickly arises, which carries off a certain number, perhaps a majority of the claimants. Those which survive have sufficient, though it may be a scanty subsistence; while, had all lingered on, all must have perished, and the race would be extinguished. In relation, however, to animals which are spread over the earth so extensively as the horse, this law is probably intended to prevent excessive multiplication, rather than to preserve the species, which could hardly be all endangered in so many different places at the same time.

As yet, the existence of such a law has been little observed, and numerous examples of its operation can not be cited. "On some of the dry and sultry plains of South America," says an excellent writer, "the supply of water is often scanty, and then a species of madness seizes the horses, and their generous and docile qualities are no longer recognised. They rush violently into every pond and lake, savagely mangling and trampling upon one another, and the carcasses of many thousands of them destroyed by their fellows [and by the disease ?] have occasionally been seen in and around a considerable pool. This is one of the means by which the too rapid increase of this quadruped is, by the ordinance of nature, here prevented."* When a scarcity of food prevails among wild animals, it is very likely that some cause arises to diminish the demand. Among domestic animals, frequent abortions and barrenness may in many instances be traced to the famine of a severe winter. It is difficult to conceive how any deficiency of air can occur to the free dwellers of the forest and the desert. Yet such an event is possible; I see no absurdity in supposing that animals might congregate in such extraordinary multitudes, that the air would be contaminated and become destructive of those by whom it is breathed.

It is said that horses have been seen in droves of ten thousand. Were several of these herds by any chance thrown into one, no place could afford sufficient nutriment to maintain them; and it is probable that the air would then receive power to destroy a few, lest famine should destroy all. It may be true that nothing of this kind has ever been observed to take place among any mass of untamed animals. There are other agents which vigilantly guard against excessive multiplication. The contamination of the air may be the last and most potent resource. But though rarely, or it may be never, occurring in the wilderness, the event is frequent in domesticity. The number of horses confined together even in the largest and most crowded stable, bears no proportion to the multitudes which compose a wild drove; yet, considered in relation to the small quantity of air by which they are surrounded, the number is excessive. The difference between the number of the horses and the quantity of air, is greater than it is ever known to be among wild horses. Hence, stabling has introduced a disease that falls very rarely, perhaps not at all, upon the untamed portion of the species. I allude to glanders.

This disease has never been seen among wild horses, and it is hardly known where the European mode of stabling has not been tried. That it can be produced by bad air, or by the want of pure air, is generally admitted. "In the expedition to Quiberon, the horses had not been long on board the transports when it became necessary to shut down the hatchways (we believe for a few hours only); the consequence of this was that some of them were suffocated, and all the rest were disembarked either glandered or farcied."*

* Mr, Youatt - The Horse. Lib. Use. Knowledge, p. 8.

[We have no doubt that these horses were diseased when shipped, and that the confinement was merely the occasion of a quicker development of the disease.]

Stables are never so perfectly close as to suffocate the horses, and they are very rarely so close as to be the sole cause of glanders or farcy. When these diseases appear in a stable, bad air may possibly be the only cause; but in general the air is assisted by excessive work, or bad food, or by both. Setting these destructive diseases out of the question, chronic cough, blindness, and common colds, form the principal evils of a stable in which the air is mingled with effluvia arising from the dung and the urine. And loss of vigor, imperfect health, and imperfect strength, are, in ordinary cases, the principal consequences of breathing air which is deficient in oxygen. Where the air is still more impure, and still more deficient, the evils are more numerous, and more serious.

When a stable is opened in the morning, if the walls or the woodwork be moist and perspiring, the stable is too close. If the air irritates the eyes and the nostrils, the stable is dirty as well as close. If the air is not comfortably warm, the stable is too open.

* Percivall's Lectures, vol. iii., p. 405.