72 A. W. Stervart on 



that such a conversion of one element into another could be 

 produced by the action of the alpha-particle from niton. 



Last year, however, Sir Ernest Rutherford, working in a 

 different field, was able to show that a collision between an alpha- 

 particle and a nitrogen atom gives rise to some particles which 

 have at most the mass of two hydrogen atoms. This evidence 

 seems to indicate that the nitrogen atom is disintegrated during 

 the collision and that some of its fragments are hydrogen atoms.* 

 It thus appears that in the laboratory it is possible to decompose 

 even one of the " stable " elements into simpler materials. 



The question of elemental synthesis seems also to have been 

 solved, though Professor Collie, who did the work, has never 

 claimed success in this direction, preferring to give his results 

 without hazarding any hypotheses as to their cause. He showed 

 that when electrical discharges are passed through hydrogen at 

 low pressure in a tube, much of the hydrogen vanishes and helium 

 makes its appearance in the vessel. Every test was applied which 

 would prove leakage in the apparatus. For example, the dis- 

 charge tube was surrounded by another tube and the space 

 between the two tubes was completely evacuated ; yet the helium 

 still appeared in the inner tube when the discharge was passed 

 through the hydrogen. Other checks were applied Avhich would 

 have established the existence of a leak even if the actual orifice 

 were too small to be detected. In view of these results, it seems 

 most probable that under the influence of the discharge some of 

 the hydrogen is built up into helium ; for no other hypothesis 

 can account for the facts. If this be the correct explanation, 

 Collie's results form a laboratory parallel to Lockyer's " down- 

 grade " process in stellar evolution ; for in the gaseous stars we 

 have vast masses of gas, much of which is hydrogen, under very 

 low pressures and subjected to violent electrical stresses — -if the 

 electrical and magnetic conditions of the solar globe be assumed 

 in the stars. 



* This result appears tu confirm l^rout's view that atoms are built up 

 from hydrogen. 



