576 EEPORT— 1886. 



together ; phosphorus and oxygen would mix without union ; hydrogen and 

 chlorine would show no tendency to closer bonds ; and even fluorine, that energetic- 

 gas which chemists have only isolated within the last month or two, would float 

 about free and uncombined. 



Outside this space of free atomic matter would be another shell, in which the 

 formed chemical elements would have cooled down to tbe combination-poiut, and 

 the sequence of events so graphically described by Mr. Mattieu Williams in ' The- 

 Fuel of the Sun ' would now take place, culminating in the solid earth and the 

 commencement of geological time. 



And now I must draw to a close, having exhausted not indeed my subject, but 

 the time I may reasonably occupy. We have glanced at the difficulty of de&ning 

 an element ; we have noticed, too, the revolt of many leading physicists and chemists 

 against the ordinary acceptation of the term element. We have weighed the im- 

 probability of their eternal .self-existence or their origination by chance. As a re- 

 maining alternative we have suggested their origin by a process of evolution like 

 that of the heavenly bodies according to Laplace, and the plants and animals of 

 our globe according to Lamarck, Darwin, and "Wallace. In the general array of 

 the elements, as known to us, we have seen a striking approximation to that of the 

 organic world. In lack of direct evidence of the decomposition of any element, 

 we have sought and found indirect evidence. We have taken into consideration 

 the Light thrown on this subject by Prout's law, and by the researches of ]\Ir. 

 Lockyer in solar spectroscopy. We have reviewed the very important evidence 

 dra-wn from the distribution and collocation of the elements in the crust of our 

 earth. We have studied Dr. Carnelley's weighty argument in favour of the com- 

 pound nature of the so-called elements from their analogy to the compound radicles. 

 We have next glanced at the view of the genesis of the elements ; and, lastly, we 

 have reviewed a scheme of their origin suggested by Professor Reynolds's method 

 of illustrating the periodic classification. 



Summing up all the above considerations we cannot, indeed, venture to assert 

 positively that our so-called elements have been evolved from one primordial 

 matter : but we may contend that the balance of evidence, I think, fairly weighs 

 in favour of this speculation. 



This, then, is the intricate question which I have striven to unfold before you, 

 a question which I especially commend to the young generation of chemists, not 

 only as the most interesting but the most profoundly important in the entire 

 compass of our science. 



I say deliberately and advisedly the most inferesfhif/. The doctrine of evolu- 

 tion, as you well know, has thrown a new light upon and given a new impetus 

 to every department of biology, leading us, may we not hope, to anticipate a 

 correspotiding wakening light in the domain of chemistry h 



I would ask investigators not necessarily either to accept or to reject the hypo- 

 thesis of chemical evolution, but to treat it as a provisional hypothesis ; to keep it 

 in view in their researches, to inquire how far it lends itself to the interpretation 

 of the phenomena observed, and to test experimentally every line of thought which 

 points in this direction. Of the difficulties of this investigation none can be more 

 fully aware 'than myself. I sincerely hope that this, my imperfect attempt, may 

 lead some minds to enter upon the study of this fundamental chemical question, 

 and to examine closely and in detail what I, as if amidst tbe clouds and mists of a 

 far distance, have striven to point out. 



The following Papers were read : — 



I. On the Absorption Spectra of Uranium Salts. 

 By "W. J. Russell, F.R.S., and W. Lapraik, F.G.S. 



Well-marked absorption bands are produced in the visible spectrum by the differ- 

 ent salts of this metal. The salts are divided into two very distinct classes, uranoua 

 and uranic salts, and each class gives an entirely different absorption spectrum ^ 



