166 HISTORY OF CHEMISTRY. 



on the strength of a few facts, being, as it were, 

 irresistibly recommended by the clearness and sim- 

 plicity which the notion possessed. Mr. Dalton 

 himself represented the compound atoms of bodies 

 by symbols which professed to exhibit the arrange- 

 ment of the elementary atoms in space as well as 

 their numerical proportion ; and he attached great 

 importance to this part of his scheme. It is clear, 

 however, that this part of his doctrine is not essen- 

 tial to that numerical comparison of the law with 

 facts, on which its establishment rests. These hypo- 

 thetical configurations of atoms have no value till 

 they are confirmed by corresponding facts, such as 

 the optical or crystalline properties of bodies may 

 perhaps one day furnish. 



Sect. 2. Reception and Confirmation of the 

 Atomic Theory. 



IN order to give a sketch of the progress of the 

 Atomic Theory into general reception, we cannot 

 do better than borrow our information mainly from 

 Dr. Thomson, who was one of the earliest converts 

 and most effective promulgators of the doctrine. 

 Mr. Dalton, at the time when he conceived his 

 theory, was a teacher of mathematics at Manchester, 

 in circumstances which might have been considered 

 narrow, if he himself had been less simple in his 

 manner of life, and less moderate in his worldly 

 views. His experiments were generally made with 

 apparatus of which the simplicity and cheapness 



