instance—but one solitary female in a state of fecundity; and the parasitical distemper unfolded itself so fiercely as to cause the death of three of these sheep on which the test was allowed to run its course; whilst the other three sheep, having been restored in time to a recoverable condition just as they were about to drop off, were thoroughly cured, without any special treatment, by the sole influence of good food and ordinary hygienic attention.

Other tests, similar to these experiments, were applied to dogs, horses, and horned cattle. A lean and scraggy dog, covered with parasites and eruptions, with eyes running foul humour, a dog which could neither run nor stand, and which was reduced to the last stage of wasting marasmus, was rescued from the jaws of death and thoroughly cured without special treatment, by the sole influence of a rich restorative diet. This dog afterwards became a fine hunting hound, beautiful in shape, and admirable for his sportive attributes.

These experiments having been submitted to the judgment of the Académie des Sciences in Paris, were honoured with its approval, and the reports concerning them were printed at the Academy's expense, and crowned at the competitive examination.

The vital resistance of horned cattle is so feeble, that those animals which are periodically exhibited in the north of London, though certainly chosen from among the most healthy and robust, could not herd together in large numbers for the space of a month in the Agricultural Hall at Islington, without sinking under infectious and contagious diseases—almost one and all. Under the conditions in which we see them in that Show, a single month would be sufficient to produce almost their complete destruction; for even a single week, which is the usual duration of their confinement, affects them so much as to render a large proportion of them unhealthy.

Every one knows how apt cavalry horses are to sicken and die off during a campaign. Every one has heard of the fearful ravages amongst the horses of the Allied armies during the Crimean war, when many companies were dismounted owing to this mortality.

Let us now transport ourselves in thought into the middle of those immense steppes where vast and innumerable herds of herbivorous animals are being bred for our supply, and consider what will be the effects on their health and life if they should be afflicted with a scarcity of forage, in consequence of this long dry summer.

It is unnecessary to say that there exist in Russia, in Hungary, in Australia, in North and South America, and in many other parts of the globe, large tracts of country which are still uninhabited, whose uncultivated soil supplies with food great numbers of sheep and cattle. These spacious tracts, known as moorlands or steppes, particularly abound in Russia, on the banks of the Wolga, the Don, the Dnieper; in Hungary, on the banks of the Danube; and also in South America, in the republics of Venezuela, New Granada, Columbia, &c.

Now, in hot and rainy seasons these steppes teem with rich and luxuriant verdure; the plants growing up in the marshes are prolific and abundant, and even those parts of the wild moors which produce nothing but heath are capable of feeding and fattening flocks and herds.

Under conditions so auspicious as these, animals may still suffer, but in what way? By excess of food, or repletion. They are in general robust and healthy, and thus fortified they inhale without detriment the deleterious gases of oxygen with carbon, carburetted hydrogen and the like, exhaled by the plants which grow out of the swampy soils. Thus protected, too, they are proof against the fluctuations of the seasons, and against every injury which threatens them; and their strong and sound condition enables them to sustain the fatigues of their long and arduous journeys, and to supply the rich countries of the West with their flesh, fleece, and hides.

When the seasons have thus conveyed a due proportion of heat, water, and electricity to the elements of the soil, both plants and animals conduce to the comfort and health of man, and fulfil his expectations. But the laws of nature are involved in mystery. Good and evil go hand in hand—death and life travel close together—and a few years of prosperous harvests are almost invariably followed by blight, barrenness, and scarcity. Most men think only of the present time, and this imprudence and want of foresight prevent farmers and great cattle proprietors from collecting and holding in reserve the requisite stores of sustenance to supply their sheep and oxen during these barren seasons. Sickness then breaks out, and these helpless creatures perish in vast numbers, to the detriment of their owners' best interests.

And truly, when continual rains cause the rivers to overflow, when the plains are drenched and soaked, or when a burning sun scorches the ground, herbivorous animals wander in vain from field to field in quest of sustenance to restore their strength, or of pure and healthy water to slake their thirst; their vital resistance dwindles away, deleterious gases poison and bewilder them, their blood is debased, and as Ovid says,

"Corpora fœda jacent, vitiantur odoribus herbæ."

And since these mild and harmless animals, which seem to have been created merely to clothe us, and to nourish us with their milk and flesh, have not been endowed by nature either with the intelligence, or the activity, or the cunning, or the invention, or the skill bestowed on the omnivorous and carnivorous species, hard is their fate under the pressing needs of hunger. Peaceful creatures, they browse in vain on deleterious plants on a sterile soil; their external and internal teguments now afford a favourable seat for the propagation of parasites—for the parasitogenia; and soon after a general adynamia, or relaxation of the fibres, delivers them up without resistance to the morbific elements of the infectious diseases to which they are exposed, where the languishing, the sick, and the rotting are herded together, and they are carried off by hecatombs by this wasteful and devouring typhus.

II.

We may readily conclude, from these general observations on infectious and contagious diseases, that they must have existed in all former ages; and if in our present advanced state of civilization they are so destructive, we may be sure that in those remote periods they must have been, both as regards man as well as the brute creation, the cause of general extermination, in whatever parts of the earth they prevailed. And indeed, whenever we refer to ancient or modern history, we are continually struck with the analogy which exists between the epidemic diseases signalized by the general name of Plague, and which decimated all the living beings, and those which more recently, and at the present moment, have startled the world by their fatal effects on men and animals.

Moreover, we cannot too often repeat the fact—in order that those documents relating to the past which contain useful instruction may be examined and searched into—that the physiological and pathological laws which rule and determine the phenomena of organic matter, whether in health or sickness, were, like the laws of chemistry, electricity, and astronomy, originally established at the time of creation, and that matter submits with passive obedience to the laws of transformation and transubstantiation, which are the absolute condition of life. These are the eternal laws of which a synthesis so admirable is