MIRACLES OF SCIENCE 



test tube are not to be relied upon. The test must 

 be made in the tissues of the living organism. Obvi- 

 ously a human being cannot be used for this; but for- 

 tunately the tests made with the lower animals, not- 

 ably guinea pigs, rabbits, and mice afford clues that 

 have a large measure of reliability. It is with the aid 

 of these agents that the remarkable work of recent 

 decades in combatting germ diseases has been carried 

 out. 



The attempts of Ehrlich to develop antidotes in the 

 test tube were first directed against the protozoal 

 germs of the deadly African disease called sleeping 

 sickness. Ehrlich finally developed a compound of 

 atoxyl having undoubted efficacy in destroying the 

 protozoon, called a trypanosome, that causes the dis- 

 ease. Unfortunately the remedy was found to pro- 

 duce bad after effects, sometimes causing permanent 

 blindness. But the use of the drug salvarsan, which 

 was the next important development, seems to have 

 no bad sequel. It destroys the spirochete of syphilis 

 seemingly without injury to the patient. The com- 

 plications of syphilis are so numerous that it is usually 

 desirable to supplement the use of salvarsan with 

 other "treatment. But the broad general claim that 

 this drug is a specific enemy of the germ of syphilis 

 seems fully established. 



THE QUEST OF A CANCER CURE 



A further extension of the principle of chemo- 

 therapy has been made in the attempt to discover an 

 agent that will act effectively against cancer. Ehr- 

 lich, even at the time when his remedy for syphilis 



230 



