VIRULENT DISEASES. 203 



ever he be, ' Je vmis plains de tomber dans ses mains 

 redoutables.' 



' Take care ! ' said a member of the Academy of 

 Sciences to a member of the Academy of Medicine, 

 who a short time after the incident just related was 

 proposing scientifically to * strangle ' Pasteur, ' take 

 care ! Pasteur is never mistaken.' 



One day, in 1879, a professor attached to a faculty 

 of medicine in one of the provinces announced to the 

 Academy of Sciences that he had found, in the blood 

 of a woman who had died in a hospital after two 

 weeks' illness from severe puerperal fever, a considerable 

 number of motionless filaments, simple or jointed, 

 transparent, straight, or bent, which belonged to the 

 genus Leptothrix. Engaged in studies on puerperal 

 fever, and having never met with a fact of this kind in 

 his researches, Pasteur wrote at once to this professor 

 to ask him for a specimen of the infected blood. The 

 blood arrived at the laboratory, and some days after 

 Pasteur wrote to the doctor, * Your leptothrix is no- 

 thing else than the bacterium of splenic fever.' 



This answer perplexed the doctor very much. He 

 wrote to Pasteur that he did not dispute the affirma- 

 tion, but that he proposed to control it ; that if he 

 found he had been in error he would publish it. 



Pasteur offered to send him guinea-pigs which had 

 been inoculated with splenic fever. 'You will receive 

 them still living ; they will die under your eyes. You 



