264 J. P. Cooke, Jr.—Berthelot's Thermo-Chemistry. 
problems which have been successfully solved in organic sy? 
thesis, and it is in this direction, as it seems to us, that we can 
indeed, be found that the problem cannot be solved and 
attempts to solve it may lead to results which will modify ot 
supplant our present theories. It may appear that the differ- 
ence between a chemical and a physical process is one of degree 
and not of kind; but, whatever the result may be, there can be 
no doubt that the investigation will lead to larger knowledge 
and clearer conceptions. 
