TRANSACTIONS OF SECTION B. 559 



is nothing less than the chemical elements commonly so called, the bodies as yet 

 undecomposed into anything simpler than themselves. There they extend before us, 

 :as stretched the wide Atlantic before the gaze of Columbus, mocking, tauntino-, 

 and murmuring strange riddles, which no man yet has been able to solve. 



The first riddle, then, which we encounter in chemistry is, ' What are the 

 ■elements ? ' Of the attempts hitherto made to define or explain an element none 

 satisfy the demands of the human intellect. The text-books tell us that an element 

 is ' a body which has not been decomposed '; that it is ' a something to which we 

 can add, but from which we can take away nothing,' or ' a body which increases 

 in weight with every chemical change.' Such definitions are doubly unsatisfac- 

 tory : they are provisional, and may cease to-morrow to be appUcable in any given 

 •case. They take their stand, not on any attribute of the things to be defined, but 

 on the limitations of human power ; they are confessions of inteUectual impotence. 



Just as to Columbus long philosophic meditation led him to the fixed belief of 

 the existence of a yet untrodden world beyond that waste of Atlantic waters, so to 

 our most keen-eyed chemists, physicists, and philosophers a Variety of phenomena 

 suggest the conviction that the elements of ordinary assiunption are not the 

 ultimate boundary in this direction of the knowledge which man may hope to 

 attain. Well do I remember, soon after I had obtained evidence of the distinct 

 nature of thallium, that Faraday said to me, ' To discover a new element is a very 



fine thing, but if you could decompose an element and tell us what it is made of 



that would be a discovery indeed wortli making.' And this was no new specula- 

 tion of Faraday's, for in one of his early lectures he remarked, 'At present we 

 begin to feel impatient, and to wish for a new state of chemical elements. For a 

 time the desire was to add to the metals, now we wish to diminish their number. . 

 To decompose the metals, then, to reform them, to change them from one to 

 another, and to realise the once absurd notion of transmutation are the problems 

 now given to the chemist for solution.' 



Mr. Herbert Spencer, in his hypothesis of the constitution of matter, says : — 

 ' All material substances are divisible into so-caUed elementary substances composed 

 of molecular particles of the same nature as themselves ; but these molecular particles 

 are complicated structures consisting of congregations of truly elementary atoms, 

 identical in nature and differing only in position, arrangement, motion, '&c., and 

 the molecules or chemical atoms are produced from the true or physical atoms by 

 processes of evolution under conditions which chemistry has not yet been able to 

 reproduce.' 



Mr. Norman Lockyer has shown, I think on good evidence, that, in the 

 heavenly bodies of the highest temperature, a large number of our reputed ele- 

 ments are dissociated, or, as it would perhaps be better to say, have never been 

 formed. _ Mr. Lockyer holds that ' the temperature of the sun and the electric 

 •arc is high enough to dissociate some of the so-called chemical elements, and give 

 us a glimpse of the spectra of their bases ' ; and he likewise says that ' a terrestrial 

 element is an exceedingly complicated thing that is broken up into simpler things 

 at the temperature of the sun, and some of these thuigs exist in some sun-spots, 

 while other constituents exist in others.' 



The late Sir Benjamin Brodie, in a lecture on Ideal Chemistry delivered before 

 the Chemical Society in 1867, goes even further than this. He says : — ' We may 

 conceive that, in remote time or in remote space, there did exist formerly, or 

 possibly do exist now, certain simpler forms of matter than we find on the surface 

 of our globe — a, x, I, v, and so on. . . . We may consider that in remote ages the 

 temperature of matter was much higher than it is now, and that these other things 

 existed then in the state of perfect gases — separate existences — uncombmed. . . 

 We may then conceive that the temperature began to fall, and these things to com- 

 bine with one another and to enter into new forms of existence, appropriate to the 

 circumstances in which they were placed. . . . We may further consider that, as 

 the temperature went on falling, certain forms of matter became more permanent 

 and more stable, to the exclusion of other forms. . . . We may conceive of this 

 process of the lowering of the temperature gomg on, so that these substances, 



