106 Agricultural Bacteriology. 



examination, to prevent soil contamination. There is 

 not the same danger, however, to the person making the 

 examination as the disease does not affect man. The dis- 

 posal of the carcass should be done either by burning or 

 burying it deeply in a place where it can not be washed 

 out or dogs dig it out. The skin should not be removed. 

 The place where the animal lay at the time of death 

 should be disinfected. 



If the disease breaks out in a herd, the animals that 

 show no signs of illness should be at once removed from 

 the pasture while the sick ones are confined to a small 

 range. The healthy animals should be vaccinated. 

 Here as in anthrax the vaccine contains the disease-pro- 

 ducing bacteria in a weakened form. The vaccine is 

 made by taking the meat from a fresh black-leg tumor, 

 pounding it in a mortar with a little water, and squeezing 

 the pulp through a cloth. This filtrate is allowed to dry. 

 It can be kept in this dry form for a long time. The 

 organism is weakened by heating this powder to about 

 210 F. for 6 hours. It is prepared for injection into 

 the animal by suspending the powder in water. A 

 definite mixture is made, one cubic centimeter of which 

 is injected beneath the skin of the animal. Some of the 

 commercial firms put up the vaccine in the form of a 

 small pellet which can be introduced readily beneath the 

 skin of the animal by means of a special syringe. An- 

 other form consists of a bunch of threads which are in- 

 serted beneath the skin by a special instrument. The 

 vaccine is used especially on the ranges, where large num- 

 bers of animals must be vaccinated, and it is desirable to 

 have the vaccine in as convenient form as possible. 



The Bureau of Animal Industry of the U. S. Depart- 

 ment of Agriculture sends the vaccine to the farmers 



