INTKODUCTION. XIX 



the power and range of chemical processes, apart from 

 the play of vitality. Beginning with the elements 

 themselves, can they not be so combined as to produce 

 organic compounds ? Not to speak of the antecedent 

 labours of "Wohler and others in Germany, it is well 

 known that various French investigators, among whom 

 are some of M. Pasteur's illustrious colleagues of the 

 Academy, have succeeded in forming substances which 

 were once universally regarded as capable of being 

 elaborated by plants and animals alone. Even with 

 regard to the rotation of the plane of polarisation, M. 

 Jungfleisch, an extremely able pupil of the celebrated 

 Berthelot, affirms that the barrier erected by M. Pas- 

 teur has been broken down ; and though M. Pasteur 

 questions this affirmation, it is at least hazardous, 

 where so many supposed distinctions between organic 

 and inorganic have been swept aw r ay, to erect a new 

 one. For my part, I frankly confess my disbelief in 

 its permanence. 



Without waiting for new facts, those already in 

 our possession tend, I think, to render the association 

 which M. Pasteur seeks to establish between dissym- 

 metry and life insecure. Quartz, as a crystal, exerts 

 a very powerful twist on the plane of polarisation. 

 Quartz dissplved exerts no power at all. The mole- 

 cules of quartz, then, do not belong to the same category 

 as the crystal of which they are the constituents ; the 

 former are symmetrical, the latter is dissymmetrical. 



