1870—1872 199 



our lives, and in one of the greatest subjects man could ap- 

 proach, for I should not despair of arriving by this means at a 

 very deep, unexpected and extraordinary modification of the 

 animal and vegetable species. 



" Good-bye, my dear Kaulin. Let us endeavour to distract 

 our thoughts from human turpitudes by the disinterested search 

 after truth." 



In a little notebook where he jotted down some intended ex- 

 periments we find evidence of those glimpses of divination in a 

 few summary lines : " Show that life is in the germ, that it has 

 been but in a state of transmission since the origin of creation. 

 That the germ possesses possibilities of development, either of 

 intelligence and will, or — and in the same way — of physical 

 organs. Compare these possibilities with those possessed by 

 the germ of chemical species which is in the chemical molecule. 

 The possibilities of development in the germ of the chemical 

 molecule consist in crystallization, in its form, in its physical 

 and chemical properties. Those properties are in power in the 

 germ of the molecule in the same way as the organs and tissues 

 of animals and plants are in their respective germs. Add : 

 nothing is more curious than to carry the comparison of living 

 species with mineral species into the study of the wounds of 

 either, and of their healing by means of nutrition — a nutrition 

 coming from within in living beings, and from without through 

 the medium of crystallization in the others. Here detail 

 facts. ..." 



In that same notebook, Pasteur, after writing down the fol- 

 lowing heading, " Letter to prepare on the species in connection 

 with molecular dissymmetry," added, " I could write that letter 

 to Bernard. I should say that being deprived of a laboratory 

 by the present state of France, I am going to give him the pre- 

 conceived ideas that I shall try to experiment upon when better 

 times come. There is no peril in expressing ideas a priori, 

 when they are taken as such, and can be gradually modified, 

 perhaps even completely transformed, according to the result 

 of the observation of facts." 



He once compared those preconceived ideas with searchlights 

 guiding the experimentalist, saying that they only became 

 dangerous when they became fixed ideas. 



Civil war had now come, showing, as Eenan said, "a sore 

 under the sore, an abyss below the abyss." What were the 

 hopes and projects of Pasteur and of Sainte Claire Deville now 



