CONTEMPORARY ADVANCES IN PHYSICS, XXVIII 



605 



2200 



2 



a 1200 



1000 



400 



200 



3.5 



3.0 



0.02 0.04 



0.08 0.10 

 MFV 



0.12 



Fig. 17 — Transmutation of boron by impact of protons: rate of observed trans- 

 mutation as function of K, for a very thin film and for a thick layer. (Oliphant & 

 Rutherford, Proc. Roy. Soc). 



(20), though it does not rule out the possibility that these functions 

 may have influence upon the curves. 



But not all of the curves of probability-of-transmutation versus K 

 are of the simple type of Fig. 17. There are also some which show 

 distinctly-marked peaks superimposed upon the gradual upward sweep ; 

 that of Fig. 18 for example, which relates to the transmutation of 

 beryllium by impact of alpha-particles with emission of neutrons, 

 presumably by the process 



2He4 + 4Be» = eC^^ + on^ 



and that of Fig. 19, which relates to the presumptive process, 



2He4 + ,^^AF = ^,^si^» + ,UK 



