Dr. E. J. Mills on the First Principles of Chemistry. 9 



mately based on Hobbes's analysis of sensation, and therefore 

 upon experience, appears to me unimpeachable ; nor has any 

 one yet been able to discover, either by accident or the most 

 ingenious design, a single atom or ultimate point of any kind. 

 Parts do not exist until we make them, and then they are new 

 wholes. If, for example, I cut a piece of paper into two parts, 

 it cannot be correct to say that those parts existed in the paper 

 before ; and they are now no longer parts, but two new whole 

 pieces of paper. We may proceed a step further. Water is 

 usually said to consist of hydrogen and oxygen. How can it 

 do so when they are gaseous bodies, and it a liquid, at the 

 ordinary temperature ? The answer is, Because you can obtain 

 hydrogen and oxygen from it. We might as reasonably affirm 

 that a chrysalis is a butterfly. Having added to water an 

 enormous amount of energy, the result has been two gases ; 

 resume the energy, and water is reproduced. 



Water + energy = hydrogen + oxygen. 



The common statement omits " energy " and is therefore an 

 erroneous equation ; for it leaves the student open to infer, as 

 many young students do, that water is decomposable without 

 any exertion whatever. The phenomena are, in fact, quite 

 consistent with hydrogen, oxygen, and water being either of 

 them compound or simple. Thus, instead of writing 



2 + 2H 2 = 2H 2 0, 



we might with equal exactness represent the experiments by 

 the equation 



(p + x) + (p — x) = 2p, 

 32 + 4 36 



which exhibits water as a simple body, just intermediate be- 

 tween hydrogen and oxygen. I examined this same question 

 some years ago, when investigating a kindred topic — the ideas 

 relating to chemical substance. In a memoir upon this sub- 

 ject, I pointed out that the principle of classification, as applied 

 to chemical substance, at once shows that we have been gra- 

 dually conceiving it as homogeneous, and chemical substance is 

 analytically defined as homogeneous substance. " Each element 

 is, as has been stated, homogeneous ; that is, the whole list of 

 elementic discriminants fails to show that it consists of more 

 than one thing, or that it can be made by putting two or more 

 things together. Each amine is homogeneous ; because the 

 varied application of aminic discriminants, such as potassic 

 hydrate, hydric chloride, platinic chloride, reveals one thing 

 only"*. 



* Phil. Mag. [IV.] vol. xl. p. 261. 



