CHAPTER XIV 

 CHEMOTHERAPY 



IN the foregoing chapters, we have seen that the animal body has 

 at its disposal a mechanism by means of which it is not only capable 

 in many instances of preventing infection, but even of overcoming 

 this successfully if by any chance, microorganisms have once passed 

 the outer barriers, and have gained a foothold in the tissues proper. 

 We have also seen that it is possible to introduce some of those 

 substances which the body makes use of in its defense, from without, 

 and that we can frequently turn the balance of the scales toward 

 recovery in this manner, where unaided this would have been 

 impossible, or attended by grave danger. Nevertheless we must 

 admit that only too often all our efforts to combat infection by the 

 body's own methods are in vain, and that in the majority of infec- 

 tions we are still far from a successful treatment. 



In view of the fact that in the test-tube we are able to destroy 

 microorganisms with the greatest ease, by the aid of a large number 

 of chemical preparations, the thought has naturally suggested itself 

 whether it would not be possible to assist the normal defenses of 

 the body by the administration of some of these substances. We 

 know as a matter of fact that the only specific medicinal treatment 

 of the older pharmacopeia, viz., that of malaria by means of quinine, 

 and of syphilis by means of mercury, depends upon the destructive, 

 effect of the remedies in question upon the respective parasites. 

 The recognition of this fact is of recent date, however, and does 

 not form the basis upon which the treatment of these diseases was 

 established. The discovery of the therapeutic properties of quinine 

 and mercury, in other words, was not the outcome of logical thought 

 and corresponding experimentation, but purely accidental. 



But the fact that it is actually possible to destroy some of the 

 pathogenic microorganisms in the body of an infected individual by 

 chemical means, would suggest that a similarly fortunate result might 

 be achieved with other substances in the case of other organisms. 



