CHAPTER XIV 

 CHEMOTHERAPY 



The action in vitro and in vivo of various organic and inorganic 

 compounds on Pneumococcus, and their use in the treatment of 

 pneumococcal infections. 



It would be a digression — a digression far beyond the scope of 

 this book — to treat at any length the administration of drugs 

 for the cure of infections due to pneumococci. It is assumed that 

 the reader has a special interest in the effects of chemical agents 

 on the life processes of Pneumococcus ; for those whose interest 

 extends to the more strictly therapeutic features of pneumococcal 

 disease, Heffron's Pneumonia? 01 will be found to contain an ex- 

 haustive discussion of the subject. 



In the chemical treatment of diseases of parasitic origin, the 

 agents usually employed fall into several main groups: arsenical 

 preparations, modifications of alkaloids, derivatives from coal tar, 

 metallic salts, and the usual pharmacopeial formulas. Those com- 

 pounds have been chosen that exert a selective action on the invad- 

 ing parasite rather than those that stimulate normal physiological 

 functions of the host ; in other words, those that are specific rather 

 than supportive. As with many other pathogenic bacteria, the 

 great majority of chemical agents which are noxious to the pneu- 

 mococcal cell are similarly injurious to the cells of animal tissues; 

 many are too poisonous in the animal body, possess too narrow a 

 margin of safety between therapeutic and toxic doses, or manifest 

 such undesirable side or secondary actions that their use is pre- 

 cluded. 



In pneumococcal infections the substances which have been 

 studied for specific curative properties include bile and its com- 

 ponent salts, some of the coal-tar dyes (especially the flavines), 

 such metals as gold, silver, and iodine, and derivatives of the al- 



