174 HISTORY OF CHEMISTRY. [LECTURE X. 



should offer to the opposing party definite principles upon 

 which it might be reconstructed. It was not in a position to 

 do this at first, since, up to this time, more attention had been 

 paid to overthrowing the old system than to building up a new 

 one. It is true that endeavours were made on various sides to 

 embrace all organic compounds in one uniform conception. 

 The radical theory, the nucleus theory, and the theory of types 

 had arisen, and each had its supporters ; but the very fact of 

 there being so many views, proved the insufficiency of any of 

 them. We find, then, a great deal of confusion ; the adherents 

 of the different systems were in continual strife, and a becoming 

 demeanour was not always maintained. 



Consequently, it is difficult to say which were the prevailing 

 ideas at the beginning of the fifth decade of the century. Even 

 the views as to the principles of each mode of regarding con- 

 stitution were widely at variance from one another. The school 

 of Gmelin had greatly augmented its adherents, and to the latter 

 the atomic theory appeared too hypothetical. We cannot be 

 surprised to find that chemists now begin to lean more and 

 more in this direction, since even the expression " atomic 

 weight " is gradually supplanted by the " equivalent," and the 

 latter is employed, as it had been by Wollaston, in the sense 

 of combining weight. 1 Upon the overthrow of the system of 

 Berzelius (that is to say, of the only system which, in any 

 uniform sense, embraced the whole science), and with the 

 origination of the most various hypotheses and theories, which 

 were not capable of any general application and did not seem 

 to have any promise of a long existence, there arose in the 

 minds of many a certain aversion to all speculation, which was 

 looked upon as premature and hurtful to the science. Nothing 

 was in keeping with the times except the temperate considera- 

 tion of observations, and Gmelin was the right man to represent 

 a tendency of this kind. He united boundless industry with 

 wide knowledge, and he understood how to turn both of these 

 qualities to account in his Hand-book. In adducing facts 



1 Compare Liebig, Annalen. 31, 36. 



