362 THE LIFE OF PASTEUR 



" Our researches " thus ran the report to the Academy 

 " may be summed up in the following propositions 



"I. The swine fever, or rouget disease, is produced by a 

 special microbe, easy to cultivate outside the animal's body. It 

 is so tiny that it often escapes the most attentive search. It 

 resembles the microbe of chicken cholera more than any other ; 

 its shape is also that of a figure 8, but finer and less visible 

 than that of the cholera. It differs essentially from the latter 

 by its physiological properties ; it kills rabbits and sheep, but 

 has no effect on hens. 



"II. If inoculated in a state of purity into pigs, in almost 

 inappreciable doses, it speedily brings the fever and death, 

 with all the characteristics usual in spontaneous cases. It is 

 most deadly to the white, so-called improved, race, that which 

 is most sought after by pork-breeders. 



"III. Dr. Klein published in London (1878) an extensive 

 work on swine fever which he calls Pneumo-enteritis of Swine ; 

 but that author is entirely mistaken as to the nature of the 

 parasite. He has described as the microbe of the rouget a 

 bacillus with spores, more voluminous even than the bacteri- 

 dium of splenic fever. Dr. Klein's microbe is very different 

 from the true microbe of swine fever, and has, besides, no 

 relation to the etiology of that disease. 



"IV. After having satisfied ourselves by direct tests that 

 the malady does not recur, we have succeeded in inoculating in 

 in a benignant form, after which the animal has proved refrac- 

 tory to the mortal disease. 



"V. Though we consider that further control experiments 

 are necessary, we have already great eonfidence in this, that, 

 dating from next spring, vaccination by the virulent microbe of 

 swine fever, attenuated, will become the salvation of pigsties." 



Pasteur ended thus his letter of December 3 : " We shall 

 start to-morrow, Monday. Adrien Loir and I shall sleep at 

 Lyons. Thuillier will go straight to Paris, to take care of teu 

 little pigs which we have bought, and which he will take with 

 him. In this way they will not be kept waiting at stations. 

 Pigs, young and old, are very sensitive to cold; they will be 

 wrapped up in straw. They are very young and quite charm- 

 ing ; one cannot help getting fond of them." 



The next day Pasteur wrote to his son : " Everything has 

 gone off well, and we much hope, Thuillier and I, that pre- 

 ventive vaccination of this evil can be established in a practical 



