392 LOUIS PASTEUR 



cloudiness of the culture fluids, consisting entirely of the 

 preceding parasite, and of this alone. 



Fourth observation. June fourteenth, the same individual 

 showed me a newly forming furuncle in the leu axilla: 

 there was wide-spread thickening and redness of the skin, 

 but no pus was yet apparent. An incision at the center 

 of the thickening showed a small quantity of pus mixed with 

 blood. Sowing, rapid growth for twenty-four hours and 

 the appearance of the same organism. Blood from the arm 

 at a distance from the furuncle remained completely sterile. 



June 17, the examination of a fresh furuncle on the same 

 individual gave the same result, the development of a pure 

 culture of the same organism. 



Fifth observation. July twenty-first, Dr. Maurice Rey- 

 naud informed me that there was a woman at the Lariboi- 

 siere hospital with multiple furuncles. As a matter of fact 

 her back was covered with them, some in active suppura- 

 tion, others in the ulcerating stage. I took pus from all of 

 these furuncles that had not opened. After a few hours, 

 this pus gave an abundant growth in cultures. The same 

 organism, without admixture, was found. Blood from the 

 inflamed base of the furuncle remained sterile. 



In brief, it appears certain that every furuncle contains 

 an aerobic microscopic parasite, to which is due the local 

 inflammation and the pus formation that follows. 



Culture fluids containing the minute organism inoculated 

 under the skin of rabbits and guinea-pigs produce abscesses 

 generally small in size and that promptly heal. As long as 

 healing is not complete the pus of the abscesses contains 

 the microscopic organism which produced them. It is there- 

 fore living and developing, but its propagation at a distance 

 does not occur. These cultures of which I speak, when 

 injected in small quantities in the jugular vein of guinea- 

 pigs show that the minute organism does not grow in the 

 blood. The day after the injection they cannot be recovered 

 even in cultures. I seem to have observed as a general 

 principle, that, provided the blood corpuscles are in good 

 physiological condition it is difficult for aerobic parasites to 

 develop in the blood. I have always thought that this is 

 to be explained by a kind of struggle between the affinity 







