2 8o THE POPULAR SCIENCE MONTHLY. 



vibration, all tliat we can conclude is, that whatever differences there 

 are in their weights, and whatever differences there are in their de- 

 grees of vibration, these differences are too small to be found out by 

 our present modes of measurement, and that is precisely all that we 

 can conclude in every similar question of science. 



Now, how does this apply to the question whether it is possible 

 for molecules to have been evolved by natural processes? I do not 

 understand, myself, how, even supposing that we knew that they were 

 exactly alike, we could know from that, for certain, that they had not 

 been evolved, because there is only one case of evolution that we know 

 any thing at all about, and that we know very little about yet that is 

 the evolution of organized beings. The processes by which that evo- 

 lution takes place are long, cumbrous, and wasteful processes of natu- 

 ral selection and hereditary descent. They are processes which act 

 slowly, which take a great laj^se of ages to produce their natural 

 effects. But it seems to me quite possible to conceive, in our entire 

 ignorance of the subject, that there may be other processes of evolu- 

 tion which result in a definite number of forms those of the chemical 

 elements just as these processes of the evolution of organized beings 

 have resulted in a greater number of forms. All that we know of the 

 ether shows that its actions are of a rapidity very much exceeding any 

 thing we know of the motions of visible matter. It is a possible thing, 

 for example, that mechanical conditions should exist, according to 

 which all bodies must be made of regular solids, that molecules should 

 all have flat sides, and that these sides should all be of the same shape. 

 I suppose it is just conceivable that it might be impossible for a mole- 

 cule to exist with two of its faces different. In that case we know 

 there would be just five shapes for a molecule to exist in, and these 

 would be produced by process of evolution. Now, the forms of 

 various matter that we know, and that chemists call elements, seem 

 to be related one to another very mucli in that sort of way : that is, 

 as if they rose out of mechanical conditions which only rendered it 

 possible for a certain definite number of forms to exist, and which, 

 whenever any molecule deviates slightly from one of these forms, 

 would immediately operate to set it right again. I do not know at 

 all we have nothing definite to go upon what the shape of a mole- 

 cule is, or what is the nature of the vibration it undergoes, or what its 

 condition is compared with the ether ; and in our absolute ignorance 

 it would be impossible to make any conception of the mode in which 

 it grew up. When we know as much about the shape of a molecule 

 a,s we do about the solar system, for example, we may be sure of its 

 mode of evolution as we are of the way in which the solar system 

 came about ; but, in our present ignorance, all we have to do is to 

 show that such experiments as we can make do not give us evidence 

 that it is absolutely impossible for molecules of matter to have been 

 evolved out of ether by natural processes. 



