24 INTRODUCTION. 



ciate justly his own acquisitions, and to concede to others the favor 



which he would claim for himself. 



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Probably the greatest step that has been made in chemical science 

 since the discovery of oxygen and chlorine, is in the establishment 

 of the doctrine of definite proportions, depending on the combina- 

 tion of the elements and of the proximate principles in certain fixed 

 ratios, thus unexpectedly, giving to chemistry a mathematical basis. 



