SYMPTOMATIC ANTHRAX 129 



repels the phagocytes, the bacilli develop. Inoculations on the ears or 

 the tail induce only local reactions and cause a degree of immunity. 

 The farther from the root of the tail the less marked is the effect. 

 When an inoculation into the tail has been made and the site kept 

 covered with an ice bag, the area of involvement is restricted and may 

 escape detection. On the other hand, if the site of inoculation on 

 the tail be kept covered with warm poultices the area involved is more 

 extensive and a general infection may result. 



Much has been done in the immunization of animals to this dis- 

 ease, although an ideal process has not been developed. The funda- 

 mental facts have been supplied by French investigators. At first they 

 employed intravenous injections of fully virulent, even spore-bearing 

 cultures. Cattle bear up to 6 c.c. of such cultures administered in 

 this way. A slight febrile reaction follows and after this the animal 

 is immune. As a laboratory method and in skilled hands this method 

 works, but it fails in unskilled hands in the field, because some of the 

 fluid is injected, not directly into the blood current but into the tis- 

 sues, and fatal infection follows. The second method consisted in the 

 subcutaneous inoculation of virulent cultures in the tail. In this local- 

 ity the organism develops slowly and the phagocytes finally destroy 

 them. A small pledget of cotton which has been moistened in a culture 

 is introduced under the skin on the tail. This method has been used 

 widely and successfully in Alsace-Lorraine and in Holland. A third 

 method consists in the employment of two vaccines. The first is a 

 culture heated for six hours at 100 to 104 C. ; the second is heated 

 for the same time at 90 to 95 C. These are dried, ground and dis- 

 tributed in packages bearing directions. The first vaccine is intro- 

 duced under the skin of the tail three hand's breadths from the root 

 and the second, ten to fourteen days later one hand's breadth from 

 the root of the tail. On account of the time required to make two 

 inoculations this method has been cut down to the use of one vac- 

 cine heated to from 95 to 100 C. and the inoculation is made on the 

 shoulder. 



The method of Norgaard is followed by the Bureau of Animal 

 Industry in this country. The tissue of a fresh tumor is pulverized, 

 extracted with water and strained through cloth. The filtrate is dried 

 to a brown scale, which is sent out in packages with directions for 



