UNDER THE APPLE-TREES 



conception, as it is beyond the power of conception 

 of the best of us. Yet we have to accept the atom 

 on the demonstrations of experimental science. The 

 heUum atom has been proved to be an objective 

 entity as truly as is the sun in heaven. The apparent 

 contradiction of an indivisible body is involved in 

 our habits of thought formed by our dealings with 

 ponderable bodies; we are introduced to the world 

 of chemical reactions. We cannot conceive or pic- 

 ture to ourselves just what takes place when two 

 gases unite chemically, as when hydrogen and oxy- 

 gen unite to form water. Our only resource is to 

 apply to the process mechanical images; our experi- 

 ence affords us no other. 



We fancy that the difference between two com- 

 pounds with the same chemical formula, but with 

 widely different properties, — say alcohol and 

 ether, — consists in the different arrangement of the 

 particles. Arranged in one order, they produce one 

 compound; arranged in a different order, they result 

 in a compound with different properties. Yet every 

 particle of these gases is supposed to be exactly Uke 

 every other particle. How hard, then, to conceive of 

 any mere spatial arrangement of them as resulting 

 in such widely different products. One has to think 

 of each atom or electron as a Httle world in itself, 

 containing different stores of energy or vibrating at 

 a different rate of speed, in order to see substances 

 of such different properties arising out of the differ- 

 168 



