166 INORGANIC EVOLUTION. [CHAP. 



tion of the periodic law, in which he assumes that temperature plays 

 a part in bringing about the changes in the characters of the ele- 

 ments. Brodie, in 1880, came to the conclusion that the elements 

 were certainly not elementary, because in what he called a " chemical 

 calculus " he had to assume that certain substances, supposed to be 

 elements, were really not so ; and he then threw out the very preg- 

 nant idea that possibly in some of the hotter stars some of these ele- 

 ments which he predicted might be found. Nine years afterwards, 

 Rydberg, one of the most industrious investigators of the question of 

 " series " to which I have referred, stated that most of the phenomena 

 of series could be explained by supposing that hydrogen was really the 

 initial element, and that the other substances were really compounds 

 of hydrogen ; so that he came back to Front's first view in 1815. All 

 these ideas imply a continuous action, and suggest that there was some 

 original stuff which was continuously formed into something more 

 complex as time went on. That is to say, that the existence of our 

 chemical elements as we know them does not depend upon their having 

 been separately manufactured, but that they are the result of the 

 working of a general law, as in the case of plants and animals. 



It will be gathered from the above statement that the stellar facts 

 are entirely in harmony with the highest chemical thought, and indeed 

 establish the correctness of its major contention. We may be said to 

 pass from chemical speculation to a solid chain of facts, which doubt- 

 less will be strengthened and lengthened as time goes on. In all these 

 changes we seem to be in the pre&ence of a series of complications, the 

 possibility of which depends upon 'a reduction of temperature. There 

 may have been roughly, a series of doublings, or the greater complexi- 

 ties may also have been brought about by the union of different 

 substances. In either case, as temperature falls, we get a possibility 

 of combinations which was not present before ; so that more and more 

 complex forms are produced. 



In discussing the idea of evolution, both organic and inorganic, we 

 are driven to the consideration of a first form, from which all subse- 

 quent ones are derived. 



The method of inorganic evolution must depend upon the way in 

 which complications are brought about. Although in this chapter I 

 have dealt with the received chemical view, I shall show subsequently 

 that it is not the only one we have to consider. 



' It is well to point out that the inquiries referred to in this book 

 are now not the only ones which suggest the evolution of inorganic 

 matter from some primordial element such as I suggested in 1873, to 

 explain the spectroscopic facts then available. 



I have already referred to the work recently accomplished on the 



