18GO iBtffr 101 



transforming wine into vinegar.,/ -ths^hri aging* *fo light of the 

 action of that mycoderma, endowed with the power of taking 

 oxygen from air and fixing it upon alcohol, thus transforming 

 the latter into acetic acid ; the most ingenious experiments to 

 demonstrate the absolute and exclusive power of the little plant, 

 all gave reason to Biot's affirmation that such skill in the obser- 

 vation of inferior vegetables equalled any botanist's claim. 

 Pasteur, showing that the interpretations of the causes which 

 act in the formation of vinegar were false, and tliat alone the 

 microscopic fungus did everything, was constantly dwelling on 

 this power of the infinitesimally small. " Mycoderma/' he 

 said, " can bring the action of combustion of the oxygen in air 

 to bear on a number of organic materia. If microscopic beings 

 were to disappear from our globe, the surface of the earth 

 would be encumbered with dead organic matter and corpses of 

 all kinds, animal and vegetable. It is chiefly they who give 

 to oxygen its powers of combustion. Without them, life would 

 become impossible because death would be incomplete." 



Pasteur's ideas on fermentation and putrefaction were being 

 adopted by disciples unknown to him^ " I am sending you," 

 he wrote to his father, " a treatise on fermentation, which was 

 the subject of a recent competition at the Montpellier Faculty. 

 This work is dedicated to me by its author, whom I do not know 

 at all, a circumstance which shows that my results are spread- 

 ing and exciting some attention. 



" I have only read the last pages, which have pleased me ; if 

 the rest is the same, it is a very good rdsumd, entirely conceived 

 in the new direction of my labours, evidently well understood 

 by this young doctor. 



" M. Biot is very well, only suffering a little from insomnia. 

 He has, fortunately for his health, finished that great account 

 of my former results which will be the greatest title I can have 

 to the esteem of scientists." 



Biot died without having realized his last wish , which was to 

 have Pasteur for a colleague. It was only at the end of the 

 year 1862 that Pasteur was nominated by the Mineralogical 

 Section for the seat of Senarmont. This new candidature did 

 not go without a hitch. In his study on tartrates, Pasteur, as 

 will be remembered, had discovered that their crystalline forms 

 were hemihedral. When he examined the characteristic faces, 

 he held the crystal in a particular way and said : ' ' It is hemi- 

 hedral on the right side." A German mineralogist, named 



