XX.] THEORY OF TYPES IN CHEMISTRY. 469 



theory to the so-called oxygen-acids and to the anhydrides, and 

 in whose earlier papers may be found the germs of most of the 

 ideas on classification usually attributed to Gerhardt and his 

 disciples." (Proc. Am. Assoc. Adv. Science, 1858, page 197.) 

 It will be seen, from what precedes, that I not only applied 

 the theory, as Dr. Gibbs remarks, but, except so far as Laurent's 

 suggestion goes, invented it and published it in all its details 

 some years before it was accepted by a single chemist. 



In conclusion, I have only to ask that future historians will 

 do justice to the memory of Auguste Laurent, and will, more- 

 over, ascribe to whom is due the credit of having given to the 

 science a theory which has exercised such an important influ- 

 ence in modern chemical speculation and research ; remember- 

 ing that my own publications on the subject, which cover the 

 whole ground, were some years earlier than those of William- 

 son, Gerhardt, Wurtz, or Kolbe. 



