534: The Possibility of separating Isotopes. 



Conclusions. 



The following conclusions may be drawn from the above 

 considerations and results : — 



(a) Thermodynamic theory indicates that isotopes must be 

 separable in principle even chemically under some physical 

 conditions, though the separation may be small and these 

 conditions may not be obtainable without great difficulty. 



(b) None of the physical methods considered give hope 

 of easy separation even for gaseous isotopes. When the 

 quantities dealt with are reasonably large the enrichment is 

 extremely small, and when anything like complete separation 

 is hoped for the yield is microscopic. The most promising 

 method appears to be the use of a centrifuge, provided the 

 engineering problems can be overcome. 



(c) The experimental results quoted so far as they have 

 gone cannot pretend to be conclusive either as to the 

 homogeneity of neon or to the separability of isotopes. 



Summary. 



Theoretical considerations are advanced to show that 

 elements of different atomic weights must be separable in 

 principle though possibly not in practice. 



Various possible methods of separating such substances 

 are discussed. 



Fractional Distillation or Chemical Separation may be 

 possible under suitable conditions. 



Diffusion must lead to a positive result, but the technique 

 is necessarily laborious. 



Gravitational Separation is small. Centrifugal Separation 

 appears promising, but would involve heavy outlay and 

 elaborate preparations. 



Electrical Separation, the only method offering hopes of a 

 pure product, will only yield microscopic quantities even if 

 the very serious difficulties indicated can be overcome. 



Experiments to separate the hypothetical constituents of 

 Neon are described, in which neither by fractional distil- 

 lation nor by diffusion have conclusive results yet been 

 obtained. 



Farnborough, 



Feb. 15th, 1919. 



