A slight purgative drink is often very useful for cows soon after calving, particularly if feverish, and in cases of over-feeding, when the animal will often appear dull and feverish; but when the surfeiting is attended by loss of appetite, it can generally be cured by withholding food at first, and then feeding but slightly till the system is renovated by dieting. Purgative drinks will often cure cases of red water, if taken in season. A purgative is often necessary for cows after being turned into a fresh and luxuriant pasture, when they are apt to become bound from over-feeding; but constipation does not so often follow a change from dry to green food in spring, as from a poor pasture in summer to one where they obtain much better feed. The HOOVE or HOVEN is brought on by a derangement of the digestive organs, occasioned by over-feeding on green and luxuriant clover, or other luxuriant food. It is simply the distension of the first stomach by carbonic acid gas. In later stages, after fermentation of the contents of the stomach has commenced, hydrogen gas is also found. The green food, being gathered very greedily after the animal has been kept on dry and perhaps unpalatable hay, is not sent forward so rapidly as it is received, and remains to overload and clog the stomach, till this organ ceases or loses the power to act upon it. Here it becomes moist and heated, begins to ferment, and produces a gas which distends the paunch of the animal, which often swells up enormously. The cow is in great pain, breathing with difficulty, as if nearly suffocating. Then the body grows cold, and, unless relief is at hand, the cow dies. Prevention is both cheaper and safer than cure; but if by neglect, or want of proper precaution, the animal is found in this suffering condition, relief must be afforded as soon as possible, or the result will be fatal. A hollow flexible tube, introduced into the gullet, will sometimes afford a temporary relief till other means can be had, by allowing a part of the gas to escape; but, the cause is not removed either by this means or by puncturing the paunch, which is often dangerous. In the early stage of the disease the gas may be neutralized by ammonia, which is usually near at hand. Two ounces of liquid ammonia, in a quart of distilled or rain water, given every quarter of an hour, will prove beneficial. A little tincture of ginger, essence of anise-seed, or some other cordial, may be added, without lessening the effect of the ammonia. If the case has assumed an alarming character, the flexible tube, or probang, may be introduced, and afterwards take three drachms either of the chloride of lime or the chloride of soda, dissolve in a pint of water, and pour it down the throat. Lime-water, potash, and sulphuric ether, are often used with effect.