THE IDEAS ON CONTAGION PRIOR TO 1866 229 



for the perspicacity of Henle is that he pointed out the 

 bacteria as among the beings capable of giving infectious 

 germs, and that he thus foresaw and almost enunciated 

 our present day ideas. I reply, you forget a detail 

 which is far from being insignificant. For Henle, the 

 germ of the disease was not something superposed upon 

 the sick person and independent of him, it was something 

 belonging to him, borrowing from him a sort of patho- 

 logical vitality, and able to transport it elsewhere. 

 The system of Henle is much more in consonance with 

 what one then knew of viruses, of the transmission of 

 smallpox, of vaccine, than with what one had recently 

 learned of the transmission of itch or of muscardine, and 

 we find therein nothing of the new idea brought by 

 Pasteur concerning the living virus, which can be 

 cultivated and modified outside of the organism. 



A physician of La Teste, J. Hameau, had entered upon 

 a better pathway in a paper which, written in 1836, 

 was unfortunately not published until 1847, a long time 

 after the work of Henle. Hameau, contrary to Henle, 

 had taken the itch especially as the point of departure 

 for his deductions and for his system, and all that which 

 is in accord with this premise is correct for he had truly 

 method and logic in his mind. On the contrary he wan- 

 ders when he takes up the question of miasms, to which 

 he attaches dysentery, erysipelas, and hospital gangrene. 

 For him, there was not in these cases any contagium 

 vivum, while there was such for Henle, and that shows us 

 how necessary it is to distrust words, and how much one 

 would have disturbed both Henle and Hameau by placing 

 them in the same camp, under the pretext that they had 

 the same words inscribed upon their banner. 



It is not these philosophical speculations which cause 

 science to advance. We must be grateful to all of those 

 from Columella and Varro, by way of Paracelsus, Fra- 



