PRESIDENTIAL ADDRESS.— SECTION' I. 15 



J. J. Thomson, we may " regard the corpuscles as one of the 

 bricks from which the atoms (of matter) are built up." 



For ages the alchemists endeavoured to discover some method 

 whereby one kind of matter could be changed into another, the 

 general idea being to obtain a valuable material from one almost 

 worthless, and the search after the Philosophers' stone which was 

 to transmute iron or copper into gold was carried on right into the 

 beginning of the nineteenth century. One of the chief results of 

 Dalton's labours was to overthrow the doctrine of transmutation, 

 and from the beginning to the end of the nineteenth century, very 

 few could have been found who would dare to question the im- 

 possibility of transmutation ever being effected. And yet the 

 theory is not so unreasonable as may at first sight appear, for we 

 know that it is possible to change yellow into red phosphorus,, 

 diamond into grai^hite — fortunately for South Africa the converse 

 does not hold, — while iron, when heated to 730° loses one of its most 

 characteristic properties, viz., magnetic susceptibility. Silver ako 

 can be obtained in the form of a red powder, soluble in water, and 

 many other instances could be quoted to show that apparently 

 one kind of matter could be changed into another kind, which 

 was certainly physically different and to some extent chemically 

 different. But no one has yet succeeded in changing phosphorus 

 into sulphur or silver into copper, and the chemical element was 

 considered to be a definite entity which was practically immutable. 



To some investigators, however, the thought must have often 

 occurred that some, at all events, of our so-called elementary 

 matter might conceivably be simple. The spectroscope shows that 

 very few elements give simple spectra — in fact, most of them are 

 exceedingly complex. If the spectral lines are due to periodic 

 vibrations of the electrons or corpuscles — then in the case, say, of 

 iron — very many periodic vibrations are possible, whereas, in an 

 ideal element we should expect that it would have only one vibratory 

 period, in which case its spectrum would show one line only. This 

 condition is not attained by any one element. Of course, if each 

 element should give one line only, the number of elements would 

 have to be indefinitely increased. This, I think, would not cause 

 any great confusion, as we should find that in most cases the groups 

 of elements, and not the actual elements themselves, would be 

 capable of enjoying a separate existence. 



This idea is, of course, contrary to that formerly held — still, 

 indeed, held — that all the elements were formed from hydrogen 

 or some primordial body. 



If Front's hypothesis can be considered valid. I think it is not 

 unphilosophical to consider the possibility of transmutation ; the 

 improbability is certainly very great, but not unthinkable. At 

 the end of last century the position was this : that the matter 

 composing the universe, as far as revealed by chemistry and the 

 spectroscope, was made up of about seventy different elements, 

 these elements being considered quite distinct from each other. 

 Now, we cannot regard the number of elements as absolutely fixed, 

 for several of them are present in such small quantity and are so 

 intimately combined with other elements, that great difficulty is 



