Any unnatural discharge irritates and scalds the mouth of the womb so that when the discharge ceases the mouth of the womb heals, and it is impossible to make a cow or mare breed without mechanical interference. This kind of treatment is conducive to fertility by increasing the blood supply to the part. Mechanical contrivances are now on the market for the purpose of dilating the mouth of the womb. These increase the probability of pregnancy. If the womb be opened just before service, many troublesome cases can be corrected. This is done by inserting the oiled hand and arm into the vagina, finding the opening into the womb, and gradually dilating it by inserting one or more fingers until the passage is open and free. =BIG HEAD.=--Just why bones become soft and frequently are absorbed in normal animals is not known, unless it is due to an absence of some essential bone constituent in the food or water. The disease shows that the bone is absorbed and its structure softened. As a consequence, the bone enlarges, becomes spongy and light. The disease usually starts as a swelling in the head, hence the name. Often the lower jaws are enlarged, and, as the disease progresses, the legs become affected. At the same time the animal loses weight. The treatment consists of nourishing foods, rich in the mineral constituents. Better consult a veterinarian when the disease is first noticed. =BIG JAW OF CATTLE.=--See Actinomycosis. =BIG KNEE.=--Often cattle show large bunches over the knees. These may be soft or hard. In cattle these big knees are caused by hard floors, in lying down and getting up. Big knee in horses is a little different, being more in the nature of spavin or ringbone, and in this case occurring at the knee joints. In cattle the bunch may be localized in the flesh and skin. With horses, it is an attack on the bony structure. When first noticed a blister may be used. =BIG LEG.=--See Lymphangitis. =BITTER MILK.=--Frequently germs get into the udder, and, as a result, bitter milk or blue milk or bad milk results. Sometimes the bad taste of milk is due to the odor in the stable or to the food that the cows get while pasturing. Turnips give a bad taste to the milk, as does garlic or wild onions. If the bitter taste or the blue milk is due to disease germs, then the remedy lies in the destruction of these germs. Just after milking, and each quarter thoroughly emptied, inject a warm solution of boric acid. =BLACKHEAD.=--A germ disease affecting turkeys and chickens. It is characterized by a dark purple appearance in the comb and wattles. Fowls attacked by the disease show dullness and laziness; at the same time indigestion disturbances and diarrhœa is observed. The best treatment is to kill the fowls affected just as soon as they become affected. This will prevent the disease from spreading. It is advisable to burn the bodies of the dead so as to prevent the spreading of the germs. Thorough disinfection is necessary.