2 5 2 THE POPULAR SCIENCE MONTHLY. 



Thus, then, it becomes possible to affect sheep and cattle with a 

 form of anthrax-disease so mild as to bear much the same relation to 

 the severer forms that cow-pox bears to small-pox ; and for this arti- 

 ficial affection with the mitigated disorder, Pasteur uses the term "vac- 

 cination." The question that now arises to which the whole previous 

 investigation has led up is the most important of all : Does this " vac- 

 cination " with the mild virus afford the same protection against the 

 action of the severe, that is imparted by cow-pox vaccination against 

 small-pox ? To this question affirmative answers w T ere last year ob- 

 tained by Professor Greenfield (on Professor Burdon-Sanderson's sug- 

 gestion) in regard to bovine animals, and by M. Toussaint in regard 

 to sheep and dogs ; the former, when " vaccinated " from rodents, and 

 the latter from fluids " cultivated " outside the living body after a 

 method devised by M. Toussaint, proving themselves incapable of be- 

 ing infected with any form of anthrax-disease, though repeatedly inocu- 

 lated with the malignant virus, and remaining free from all disorder, 

 either constitutional or local. The same result having been obtained 

 from experiments made by Pasteur himself, probably about the same 

 date, with charbon- virus cultivated in the manner previously described, 

 it was deemed expedient by one of the Provincial Agricultural Socie- 

 ties of France that this important discovery should be publicly dem- 

 onstrated on a great scale. Accordingly, a farm and a flock of fifty 

 sheep having been placed at M. Pasteur's disposal, he "vaccinated" 

 twenty-five of the flock (distinguished by a perforation of their ears) 

 with the mild virus on the 3d of May last, and repeated the operation 

 on the 17th of the same month. The animals all passed through a 

 slight indisposition, but at the end of the month none of them were 

 found to have lost either fat, appetite, or liveliness. On the 31st of 

 that month, all the fifty sheep, without distinction, were inoculated 

 with the strongest charbon- virus, and M. Pasteur predicted that on 

 the following day the twenty-five sheep inoculated for the first time 

 would all be dead, while those protected by previous "vaccination" 

 with the mild virus would be perfectly free from even slight indisposi- 

 tion. A large assemblage of agricultural authorities, cavalry-officers, 

 and veterinary surgeons having met at the field the next afternoon 

 (June 1st), the result was found to be exactly in accordance with M. 

 Pasteur's predictions. At two o'clock twenty -three of the "unpro- 

 tected" sheep were dead ; the twenty-fourth died within another hour, 

 and the twenty-fifth an hour afterward. But the twenty-five " vacci- 

 nated " sheep were all in perfectly good condition ; one of them, which 

 had been designedly inoculated with an extra dose of the poison, hav- 

 ing been slightly indisposed for a few hours, but having then recovered. 

 The twenty-five carcasses were then buried in a selected spot, with a 



By Dr. Grawitz, indeed, it has been recently asserted that even some of the most innocent 

 of our domestic microphytes maybe changed by artificial culture into disease-germs of 

 deadly infectivcuess. 



