SERUM THERAPEUTICS. 
487 
“ Ectozoa and entozoa have been very plentiful in all do¬ 
mestic animals, especially in dogs and horses. Ascaris meg- 
alocephala and strongylus tetracantha being the most pre¬ 
valent ; the latter in horses, causing several deaths with the 
usual symptoms. 
“ Influenza is quite common in a mild form. Actinomyco¬ 
sis, tuberculosis, and hog cholera, have also come under my 
observation in the last year.” 
(To be continued .) 
SERUM THERAPEUTICS,* 
By S. J. J. Harger, V. M. D., Phila., Pa. 
A Paper read before the Pennsylvania State Veterinary Medical Association 
at Cresson Springs, Pa., Sept. 8th, 1895. 
The discovery of serum therapeutics, now applied in prac¬ 
tice, has opened a new era in the treatment of disease. 
Although confined as yet to a limited number of diseases and 
not yet thoroughly tested, this method of treatment has opened 
a field of experimentation whose limits to-day we cannot de¬ 
fine. A general resume of the subject may not be amiss before 
this meeting. 
It is known that the vegetable alkaloids, abrine, ricine, etc., 
very poisonous to animals, can, when given in repeated and 
very small increasing doses, develop an immunity in these ani¬ 
mals which are thus able to withstand a quantity of these sub¬ 
stances rapidly fatal to those not previously treated. A 
product is formed in the system which becomes sufficiently 
abundant to neutralize the toxic action of these poisons. 
Likewise in morbid processes, the repeated introduction into 
the system of a microbe or its product called toxin , causes the 
formation in the economy of a substance called anti-toxin , 
which is capable of counteracting the pathogenic action of 
such microbes or their poisonous excretions. This, in a word, 
is the basis of the so called anti-toxin treatment. The anti-toxin 
*The experimental information is drawn from “ Annales de l’lnstitut Pasteur,” 
Sept., 1894. 
