THE CONQUEST OF DISEASE 



Harvey ex- 

 perimented 

 on himself. 



pumping out and receiving back its blood ; and 

 fifty years later the circuit was completed by 

 the discovery of Leeuwenhoeck. The last dis- 

 covery marked the beginning of modern physi- 

 ology upon which medicine and hygiene are 

 founded. When we consider the number of 

 deer shot by huntsmen, who will begrudge 

 science the few deer that Harvey sacrificed in 

 the hunting park of Charles I to demonstrate 

 the circulation of the blood? 



Before leaving Harvey, it is worthy of note 

 that he was a pioneer in the study of infective 

 sepsis, using himself for animal experimenta- 

 tion. He says. "I have myself, for experi- 

 ment's sake, occasionally pricked my hand with 

 a clean needle, and then having rubbed the 

 same needle on the teeth of a spider, I have 

 pricked my hand in another place. I could not 

 by my simple sensation perceive any difference 

 between the two punctures: nevertheless there 

 was a capacity in the skin to distinguish the 

 one from the other; for the part pricked by 

 the envenomed needle immediately contracted 

 into a tubercle, and by and by became red, hot, 

 and inflamed, as if it collected and girded itself 

 up for a contest with the poison for its over- 

 throw." 



30 



