The bacteria which cause disease, like other living organisms, may be killed by poisoning. Such poisons are known as disinfectants. If it were possible to kill the bacteria within the animal, the curing of disease would be a simple matter, but unfortunately the common chemical poisons that kill germs kill the animal also. The only thing that can be relied upon to kill disease germs within the animal, is a counter-poison developed by the animal itself and known as anti-toxin. Such anti-toxins can be produced artificially and are used to combat certain diseases, as diphtheria and small-pox in human beings and blackleg in cattle. Such methods of combating poultry diseases have not been developed, and due to the small value of an individual fowl would probably not be commercially useful even if successful from a scientific standpoint. The only available method of fighting contagious diseases of poultry is to destroy the disease germs before they enter the fowls and to remove the causes which make the fowl susceptible to the disease. Contagious diseases of poultry may be grouped into two general classes: First, those highly contagious; second, those contracted only by fowls that are in a weakened condition. To the first class belong the severe epidemics, of which chicken-cholera is the most destructive. Chicken-Cholera. The European fowl-cholera has only been rarely identified in this country. Other diseases similar in symptoms and effect are confused with this. As the treatment should be similar the identification of the diseases is not essential. Yellow or greenish-colored droppings, listless attitude, refusal of food and great thirst are the more readily observed symptoms. The disease runs a rapid course, death resulting in about three days. The death rate is very high. The disease is spread by droppings and dead birds, and through feed and water. To stamp out the disease kill or burn or bury all sick chickens, and disinfect the premises frequently and thoroughly. A spray made of one-half gallon carbolic acid, one-half gallon of phenol and twenty gallons of water may be used. Corrosive sublimate, 1 part in 5000 parts of water, should be used as drinking water. This is not to cure sick birds, but to prevent the disease from spreading by means of the drinking vessels. Food should be given in troughs arranged so that the chickens cannot infect the food with the feet. All this work must be done thoroughly, and even then considerable loss can be expected before the disease is stamped out. If cholera has a good start in a flock of chickens it will often be better to dispose of the entire flock than to combat the disease. Fortunately cholera epidemics are rare and in many localities have never been known. Roup.