166 MEMOIR OF DR. DALTON, AND 



he might be correct, but his theory cannot be introduced 

 into science at present, and in the way he introduced it, it 

 was entirely a mistake. But he has done great service in 

 early times in seeking for the distinct constitution of bodies, 

 and in asserting the constancy of combination ; whilst he 

 obtained numbers representing the constant relation of bodies 

 to each other, he failed to see that they would be reciprocal. 

 This failure at once removes him from the great discoverers, 

 and places him among those honourable and valuable labourers 

 in science whose names are read with respect by students, 

 but who cannot be recognised by mankind generally, because 

 the capacities of our minds are too small to retain more than 

 the lives of a few of the most eminent. 



The doctrine of reciprocal proportion must be taken from 

 him, and he can now no longer hold a place in the history 

 of the atomic theory other than as the author of an intelligent 

 attempt which has entirely failed. 



I feel sorry to leave him in this state, and a few kind words 

 will do little good. I believe he would have preferred the 

 truth; the honour he received was not required by him; the 

 discovery was not claimed by him; he died in 1793, before it 

 was known to be worth making. In his works he appears 

 an honest, earnest man. 



