66 THE GENETIC AND 



established by " experiment as the highest means of 

 proof." Physics as a whole, as resting on mere un- 

 proved hypotheses, may be indeed an object of inquiry 

 but not of teaching. 



Of course the same is true of chemistry ; nay, this 

 stands on much weaker feet, and is even less proved 

 than physics. The whole theoretical side of chemistry 

 is an airy structure of hypotheses such as does not 

 exist in any other science. In the last three decades 

 we have seen a whole series of the most different theories 

 rapidly succeed each other, none of which can be posi- 

 tively proved, though at least one of them is taught by 

 every professor of chemistry. But what is worst of all, 

 the common basis of all the most dissimilar chemical 

 theories, viz., the atomic theory, is as unproved and 

 improvable as any hypothesis can be. No chemist 

 has ever seen an atom, but he nevertheless considers 

 the mechanism of atoms as the highest term of his 

 science, he nevertheless describes and constructs the 

 connection of atoms in their various combinations as 

 though he had them before him on the dissecting- 

 table ! All the conceptions which we possess as to 

 chemical structure and the affinities of matter, are 

 subjective hypotheses, mere conceptions as to the 

 position and changes of position of the various atoms, 

 whose very existence is incapable of proof. Away, 



