BLACK LEG. 
361 
preference in vegetation, etc. Charbon is referred to some¬ 
times simply as anthrax or as essential anthrax, and in man as 
malignant pustule. 
In black leg the most characteristic and striking signs are the 
pronounced gaseous black tumors about the shoulders or hips, 
limbs, neck, back, etc., etc. The liver and spleen , with the ex¬ 
ception of a discoloration which is often the result of changes 
after death, are about unchanged in their volume and consis¬ 
tency. 
In charbon these pronounced gaseous tumors are absent, al¬ 
though there are occasionally enlargements about the tongue, 
or throat, particularly when the disease occurs in the horse 
species. They are nothing to be mistaken for the true black leg 
tumors, even if such did appear regularly in charbon in cattle, 
which is not the case. The liver, spleen (and some other organs) 
are changed in volume and consistency', they are gorged with 
dark, thick blood, just the reverse of livers and spleens in 
black leg. 
Both maladies are preventable by vaccination—black leg 
by one method, discovered and extensively practiced in Europe 
by Arloing, Thomas and Cornevin; charbon by another 
method, discovered and extensively practiced by Pasteur and 
his agents.* Indeed, to the man of science there seems to be 
more analogy between charbon and septicemia than between 
charbon and black leg, and the ordinary observer is more apt 
to be confused when noticing the post mortem appearances of 
charbon and Texas fever, which present lesions much alike in 
the liver and spleen. 
VACCINE AND VACCINATION. 
(Protective Virus.) 
There is no more mystery or secret about black leg vac¬ 
cine than there is about small-pox vaccine. It simply consists 
of the germ of the disease so weakened by heat or other pro¬ 
cesses as to cause fever sufficiently high, but not enough to 
* Both kinds of vaccination are practiced in this country—the virus being 
prepared by the principle of the discoverers, but by processes by which the germs 
may be applied safely by anyone, and preserved for an indefinite period. 
