244 MEMOIR OF DR. DALTON, AND 



capacities for belief must enlarge themselves rather than 

 diminish, and we shall be left behind with a small and inade- 

 quate supply of intellectual food, if we refuse to take it until 

 we have extracted its one-tenth per cent, of questionable 

 adulteration. 



The law has established itself; it is true. Our knowledge 

 of its ramifications will increase. If it had not great rami- 

 fications, we might question its own intrinsic greatness. 

 Isomorphism and isomerism are two of these, beautiful in every 

 respect, thoroughly beautiful. But they are no contradictions, 

 the number of provinces do not prove the smallness but the 

 greatness of a kingdom. Why then should they even be 

 mentioned as modifications, they may be said even to be 

 necessary results. Allotropy is itself a curious and beautiful 

 fact, and one that we may readily suppose will widen 

 itself out, perhaps even till alchemy itself shall cease to 

 be wonderful ; but it does not disprove the atomic com- 

 binations. 



We may call the ultimate particles which practically unite 

 equivalents, as Wollaston did, but we don't alter the fact, we 

 only chronicle our hesitation, and substitute a name which 

 cannot be final, as it represents only a temporary theory ; it 

 only says that the quantities are equivalent to each other, but 

 refuses to decide what these quantities are. We may call 

 them volumes, like Berzelius, but we find then that we go on 

 a wrong hypothesis, as the atomic volumes are not the same 

 as their weights in every condition, whatever might be the 

 case if all were gaseous. 



We have, in fact, found no name representing the case as 

 well as atom, and, giving due limits to the meaning of the 

 word, it represents the state of belief in the mind of every 

 chemist, whilst no fact whatever bears directly against it. 



At the same time I do not mean to advocate the atom with 

 the physical constitution given to it by Dalton, as well as by 

 Newton and the ancients, not being able to see it possible ; 



