240 CHEMICAL INFLUENCES 



In addition to these disinfectants which are used outside of the 

 human body, or appHed to its' surface only, there have come into use 

 during recent years, several disinfectants which are injected into the 

 body to kill the microorganisms in the blood. Among these might 

 be mentioned the colloidal metals, mainly colloidal silver which is sold 

 under various trade names, e.g., collargol. It is given especially in 

 pneumonia, but its action upon the bacteria directly is very insignificant, 

 though it greatly stimulates phagocytosis. Further, there is to be 

 mentioned ethoxyl, given against the protozoon of sleeping sickness, 

 and the latest and most discussed of all, salvarsan, an organic arsene 

 compound, against syphilis. 



