AUTOTHERAPY IN THE TREATMENT OF SEPTIC DISEASES IN THE HORSE. 423 
It has been readily shown by absorption tests that opsonins 
act upon the bacteria and not by stimulating the phagocytes to in¬ 
crease activity; also by comparative tests, that the opsonic and 
bactericidal power of the blood serum in an infection do not run 
parallel, and therefore are distinct entities. 
The present day management of bacterial infections, outside 
of hygiene, sanitation, etc., is summed up in one word, immunity. 
Immunity means not only the non-susceptibility of an individual 
to a given disease and the power to resist the infection, but also 
the mechanism by means of which a cure is effected. 
There are two* forms of immunity, passive and active. Pas¬ 
sive immunity is produced by injecting protective substances man¬ 
ufactured in the body of another animal; antitoxins. The diseases 
caused by bacteria that produce soluble extra-cellular toxins in 
their growth are the only ones from which antitoxins are made. 
Most bacteria produce intra-cellular toxins, the toxins being 
bound up in the bodies of the bacteria. 
Active immunity is the immunity induced by the production 
of immune or protective substances within the. individual. This is 
the form of immunity with which we here will deal. Wright’s 
method of treating- infectious diseases by small infrequent injec¬ 
tions of sterile bacterial vaccines consisting- of the organisms caus- 
ing the disease has to a great extent revolutionized the treatment 
of bacterial diseases. Just how and why it acts, we may not be 
able to tell. We know it stimulates the immunizing apparatus 
into activity and that we are copying nature’s own methods; that 
is the spontaneous cure of infectious diseases by autoinoculations. 
Massage, cupping, counter-irritation, Bier’s hvperemic treat¬ 
ment, hot anch cold applications and many other forms of treat¬ 
ment act in this way, namely, increasing autoinoculation. This 
gives an ideal explanation of the beneficial results obtained in the 
application of mustard to the chest in pneumonia cases, where the 
infecting agent, with the products of its metabolism cong'regates 
in the lungs. This is really a form of natural autotherapy, or so- 
called autoinoculation. Injection of bacterial substances stimu¬ 
lates the body cells to produce the protective agents. 
