58 



SCIENCE. 



[N. S. Vol. XXI. Xo. 524. 



turies. but nobody thought of looking for 

 them in cast iron until after JMoissan made 

 his experiments a few years ago. 



If we accept Lockyer's conclusions as 

 to the state of things in the sun, we could 

 undoubtedly break up many of the ele- 

 ments if we could hold them long enough 

 at 6000° C. One ditficulty is to get the 

 temperature, and of course we must be 

 cautious about conclusions based on simpli- 

 fied spectra. Many people have thought 

 that radium was to be the catalytic agent 

 which was to change all the elements; but 

 the recent work of Rutherford seems to 

 put an end to this idea. If radio-active 

 lead, tellurium and bismuth are merely 

 these elements plus the radium emanation 

 or one of its decomposition products, there 

 is very little evidence to show that any of 

 our well-established elements are undergo- 

 ing any change from contact with radio- 

 active substances. 



Another possibility which has been sug- 

 gested is that we could change our elements 

 if we could pump energy into them and 

 change their energy content. This would 

 have to be done electrically if at all. I 

 have been told that Stas was busy during 

 the last years of his life trying to change 

 sodium into something else by an electrical 

 process. The difficulty is to pump energy 

 into the element. Passing a heavy cur- 

 rent through a metal produces no effect 

 that we know of other than to raise the 

 temperature. Taking the element in the 

 state of gas enables us to employ a higher 

 potential difference, but here the effective- 

 ness of the method is limited by the appear- 

 ance of the arc. The first stage in the 

 problem would, therefore, be the attain- 

 ment of the highest possible potential dif- 

 ference without causing arcing. In view 

 of the remarkable insulating action of gases 

 under high pressure, it seems as though 

 the silent discharge through compressed 

 gases were the thing to try. The difficul- 



ties people had in proving the dissociation 

 of water at high temperatures makes us 

 realize the possibility that we might decom- 

 pose our elements and never know it, owing 

 to the recombination taking place at once. 

 If we are to simplify our elements by 

 pumping energy into them, it appears that 

 we should work with gases under high pres- 

 sure, with the highest potential difference 

 compatible with the absence of sparking, 

 and with some application of the principle 

 of the hot-cold tube. 



AVhile the methods of extremely high 

 temperature and of high electrical stress 

 have much to commend them on paper, 

 they are liable to fail owing to the diffi- 

 culty of attaining the proper temperature 

 or the proper electrical stress. The ideal 

 method would be to find a catalytic agent 

 which would accelerate the rate of change 

 and which would eliminate what we should 

 then call the instable elements. Since 

 there is no immediate prospect of our being 

 able to predict the suitable catalytic agent 

 and the conditions under Avhich it is to be 

 used, we must ask ourselves what is the 

 scientific method of attacking the problem 

 of the transmutation of the elements. 



The answer is a simple one. \Ye must 

 stai't with the simplest case, study that 

 thoroughly, and work up gradually to the 

 more difficult tasks. We should begin with 

 the cases in which we know a change is 

 possible and should study the allotropic 

 forms of the elements. At present our 

 knowledge of these is disgracefully incom- 

 plete. We know a little about sulphur, 

 phosphorus, carbon, selenium and tin ; but 

 even for these few elements our knowledge 

 is incomplete and it is especially unsatis- 

 factory in matters bearing on the rate of 

 change. In most cases the change from 

 one allotropic form to the more stable one 

 is fairly slow. It is not even easy to get 

 lai'ge amounts of gray tin. On the other 

 hand, Saunders discovered, (juite by ac- 



