2SS 



considering the energy of the recoil as equal 

 and opposite thai of the a particle, the energy 

 of recoil of mass M is \ "j 1 MV-, therefore total 



energy is •' mn[l + -^j 1'V- -f E where 

 E is the energy of the (3 and A rays absorbed under 

 these conditions. 

 1.38 X 10'' ergs per second corresponds to heal 



emission of 118 grams calories per hour. 

 Heating effect of emanations 94..") calories per hour. 

 Observed values 94 calories per hour; calculated 94.5 

 calories per hour. 



Rutherford and Robertson made an experimental determination to sec- 

 how accurately this theoretical value harmonized with the experimental 

 value and found a very close correspondence between the two values. This 

 agreement led Rutherford to say that "there thus appears to be no doubt 

 that the heat emissions of radium can be accounted for by taking into 

 consideration the energy of the radiations absorbed." (The heat emitted 

 is 2.44 X 10 n calories per gram). 



He gives an interesting comparison as to the amount of energy set free 

 in the action accompanying the expulsion of the rays, as follows: "the 

 heat emitted during the combination of 1 cc. of H and to form H4) is 

 about 2 gram calories; the emanation during its successive transformations 

 thus gives out more than ten million times as much energy as the com- 

 bination of an equal volume of H and to form water although the latter 

 reaction is accompanied by a larger release of energy than that of any other 

 known to chemistry." 



Further, "the energy emitted by radioactive substances is manifest during 

 the transformation of the atom and is derived from the initial energy of the 

 atoms themselves. The enormous quantity of energy released during the 

 transformation of active matter shows unmistakeably that the atoms them- 

 selves must contain a great store of internal energy;" "undoubtedly this is 

 true of all but it is only perceived in the case of those which undergo atomic 

 transformation. ' ' 



Experiments conducted within the past three years at Munich in determ- 

 ining the interference effects produced by the passage of X-rays through 

 crystalline substances have shown that X-rays possess many of the properties 



