(84.) _Frequent change of Pasture necessary._--Sheep ought never to be permitted to remain too long on one pasture:--Great benefit will be derived from their removal from time to time to different parts even of the same farm, by which arrangement a change of herbage will be ensured. No animal can be kept for any length of time in health, if restricted to one unvarying routine of diet. This has been satisfactorily proved by the experiments of Majendie, who found that health could not be sustained on one or even two kinds of food beyond the thirtieth day. Now, though such immediate injury cannot result to a flock from retention on a particular pasture, owing to the variety of sustenance being considerable, yet proportional harm will ensue sufficient to induce us not to repeat the risk. Nature, the best of guides in all that relates to the protection of her creatures, is no where more pointed in her directions than on this head. A necessity for a variety of food, and a desire to secure it, are implanted in the disposition of every animal; and where is the creature more prone to extensive rambles than the sheep? We limit it to a paltry pasture-ground of roods and acres, but does it not show, by its determination to transgress our barriers, that such is not the treatment nature has designed for it? There is something more than wildness of character, and restless disposition, in the powerful attempts it continually makes to defy our artificial boundaries. There is in these efforts a longing for fresh fields and other herbage, an instinctive feeling that all is not as it ought to be; and yet we attend not to the hint! Nothing will conduce so much to the health of the sheep, and to the speedy taking on of fat, as the frequent shifting of the flock. Disease will doubtless still affect the animals, but illness will be rare, and mortality diminished, if by the care of their rulers, they are enabled to obtain what instinct tells them is the best of medicine.