294 THE LIFE OF PASTEUR 



For it was sufficient that some infected blood should have 

 remained on the ground, for germs of bacteridia to be found 

 there, perhaps years later. How often was such blood spilt 

 as a dead animal was being taken to the knacker's yard or 

 buried on the spot ! Millions of bacteridia, thus scattered on 

 and below the surface of the soil, produced their spores, seeds 

 of death ready to germinate. 



And yet negative facts were being opposed to these positive 

 facts, and the theory of spontaneity invoked! "It is with 

 deep sorrow," said Pasteur at the Academic de Medecine on 

 November 11, 1873, "that I so frequently find myself obliged 

 to answer thoughtless contradiction ; it also grieves me much 

 to see that the medical Press speaks of these discussions in 

 apparent ignorance of the true principles of experimental 

 method. . . . 



" That aimlessness of criticism seems explicable to me, how- 

 ever, by this circumstance that Medicine and Surgery are, 1 

 think, going through a crisis, a transition. There are two oppo- 

 site currents, that of the old and that of the new-born doctrine ; 

 the first, still followed by innumerable partisans, rests on the 

 belief in the spontaneity of transmissible diseases ; the second 

 is the theory of germs, of the living contagium with all its 

 legitimate consequences. ..." 



The better to point out that difference between epochs, 

 Pasteur respectfully advised M. Bouillaud, who was taking 

 part in the discussion, to read over Littre^s Medicine and 

 Physicians, and to compare with present ideas the chapter on 

 epidemics written in 1836, four years after the cholera which 

 had spread terror over Paris and over France. " Poisons and 

 venoms die out on the spot after working the evil which is 

 special to them," wrote Littr6, " and are not reproduced in the 

 body of the victim, but virus and miasmata are reproduced and 

 propagated. Nothing is more obscure to physiologists than 

 those mysterious combinations of organic elements ; but there 

 lies the dark room of sickness and of death which we must try 

 to open." " Among epidemic diseases," said Littr in another 

 passage equally noted by Pasteur, " some occupy the world and 

 decimate nearly all parts of it, others are limited to more or 

 less wide areas. The origin of the latter may be sought either 

 in local circumstances of dampness, of marshy ground, of 

 decomposing animal or vegetable matter, or in the changes 

 which take place in men's mode of life." 



