ATOMIC THEORY OF MATTER 



showed that definite relations existed between the 

 weights of the constituent elements. 



Charles Frederic Wenzel (1740-1793) found that 

 the amount of basic oxides required to form neutral 

 salts with a given acid was proportional to the weight 

 of the oxides required to saturate one and the same 

 amount of another acid. These results he published in 

 1777. The law of definite and multiple combinations 

 was not, however, finally and indisputably established 

 until the publication of Dal ton's Atomic Theory of 

 Chemistry reduced to order and simplicity the pre- 

 viously disconnected and unexplained phenomena of 

 chemical combination. 



John Dal ton (1766-1844), mathematician, physi- 

 cist and chemist, was the son of a weaver of woolens, 

 in very poor circumstances, at Eaglesfield, in Cum- 

 berlandshire, England. He and his parents belonged 

 to the Society of Friends. He was sent to a school 

 near his home, kept by one of his own sect, at an 

 early age. When the boy was less than twelve years 

 old his teacher told his father that he could teach 

 him nothing more, and urged him to send him where 

 his rare abilities could receive the benefits of a Uni- 

 versity culture. This his father could not do ; he was 

 obliged to keep him at home to assist him in his work. 

 For two years he thus remained, and, in order to re- 

 tain what he had learned, he taught in the winter 



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