The reduction or prevention of sudden plethora was formerly availed of to lessen the number of victims and it is well to still bear in mind that this has an appreciable though limited effect. As a means of reducing plethora a free bleeding was resorted to when the period of yearly prevalence approached, and no less when the disease had already appeared in a herd. I can mention an instance in which infection was carried on the fleam from the first animal bled (the sick one) and caused the fatal infected swelling around the phlebotomy wound in the next seven animals operated on. Another objection to phlebotomy is the tendency to a rapid reproduction of blood, which the depletion brings about, and the supervention of a greater danger than before, in the course of a month or more. Purgatives and diuretics are somewhat less objectionable in this sense. Careful feeding to keep the animal constantly in good condition does something to obviate sudden plethora and its attendant dangers, and thus an allowance of grain or linseed cake through winter and early spring, or when the pastures are bare, will bring the animals through in fine condition, and ward off the danger that comes from a sudden access of rich aliment. Another measure was the insertion of a seton in the dewlap. The theory was to counteract plethora but the benefit probably came rather from the formation of an actively granulating wound, which came in contact with the ground and received the bacillus, but in which the abundance of air, and of active leucocytes checked the propagation of the germ and the occurrence of a fatal infection. A certain grade of immunity was the natural result in many cases. _Immunization._ As the first attack of emphysematous anthrax secures for the subject of it immunity against a second, we are furnished with a reasonable basis for the practice of artificial immunization. This has been attained by a variety of methods, the essential feature of each being the subjecting of the system of the animal to be treated, to the action of the toxins of the specific bacillus. 1st. A culture of the bacillus made in the thermostat at 42 C. (107.6° F.) so as to prevent the formation of spores is then sterilized by heating to 100° C. for one hour and then injected subcutem in a dose of 2 drams, to be repeated on the second day. This, like all the other methods named should be done by some one accustomed to bacteriological manipulation and the sterilization completed by superheating the neck of the vessel containing the mixture. Any germs escaping on the hands, instruments or other objects used will prove fatal in spite of all the appearance of precautions. 2d. Roux sterilized his cultures by filtering them through a porcelain (Pasteur) filter and using only the filtrate for injection. This requires even greater precaution in manipulation as what is left in the filter is most virulent, and must be thoroughly sterilized to obviate dangers from its dissemination.