As salt is one of the principal constituents of the blood, and as it is present in the various tissues of the body, and as its ingestion is necessary for the animal economy, for the maintenance of its health, and consequently for the due development of the several organs, and the invigorating effects it exerts over their functional activity, we will now consider it in the relation it holds to animal and vegetable life. By the great majority of land animals salt is evidently an article much relished, for in those districts where salt springs and lakes are prevalent, many quadrupeds and birds are invariably to be seen.[50] They frequent these spots in great numbers, and very seldom migrate to those districts which are deficient in salt, or, if they do, very speedily return; these animal instincts are indicative that they are aware of its bracing qualities, and experience the salubriousness of the atmosphere, which naturally is impregnated with a fair amount of salt, which has risen through the media of exhalations from the water or evaporation of the same. In the Ruminantia the beneficial and, indeed, the salutary action of salt is remarkably observable, for it counteracts in this class of animals the deleterious effects of rainy weather, damp pasturage, and damaged fodder. It also imparts a consistency to the fat, and renders the meat more palatable and wholesome. All cattle, without an exception, thrive best if they are supplied with salt; and they will consume no small quantity. Horses will, on the average, consume daily six ounces; cows, four ounces, and will, it is said, secrete a larger quantity of milk, and of a much richer quality, than those from which salt is usually withheld. Sheep will consume half an ounce daily, and they are not affected with the rot, as is so frequently the case in low-lying marshy districts where they drink water in which there are myriads of the fluke-worm, embryonic and developed, especially after heavy rains or inundations, as, for instance, a river overflowing its banks. It is a fact which farmers and graziers should by no means lose sight of, that these worms are totally destroyed by giving sheep a certain amount of salt during moist and wet seasons, and in those localities which are generally in a state of humidity.