Multiple Proportions of the Atomic Weights. 85 



of error is as incumbent on an investigator of nature, as it 

 is to enlarge the boundaries of science. 



Chemists would do well to profit by the lessons to be 

 derived from a study of the history of their science ; for 

 just as the animistic delusion of phlogiston dominated and 

 retarded the progress of chemistry during the last century, 

 so the notion of a periodicity in the atomic weights is the 

 most remarkable illusion connected with the science of the 

 present century, and equally detrimental to its future 

 progress. 



In conclusion, I would exhort all teachers of chemistry, 

 whose aims are higher than to be mere phonographic ex- 

 ponents of other men's opinions, to examine for themselves 

 the numerical relations of the atomic weights to which 

 attention has been directed ; as great responsibility rests 

 upon those who continue the teaching of science in the 

 Universities and Public Schools on foundations which a 

 very limited exercise of the comparative faculty would 

 prove to be false. 



