MEMORANDUM
                                
              Much experimentation on atomic desintegration was done during the 
 
past five years, but up to this year the problem of liberating nuclear 
 
energy could not be attacked with any reasonable hope for success. Early 
 
this year it became known that the element uranium, can be split by neut-
 
rons. It appeared conceivable that in this nuclear process uranium itself 
 
may emit neutrons, and a few of us envisaged the possibility of liberating 
 
nuclear energy by means of a chain reaction of neutrons in uranium.
 
     Experiments were thereupon performed, which led to striking re-
 
sults. One has to conclude that a nuclear chain reaction could be main-
 
tained under certain well defined conditions in a large mass of uranium. 
 
It still remains to prove this conclusion by actually setting up such a 
 
chain reaction n a large-scale experiment.
 
              This new development in physics means that a new source of power 
 
is now being created. Large amounts of energy would be liberated, and 
 
large quantities of new radioactive elements would be produced in such a 
 
chain reaction.
 
     In medical applications of radium we have to deal with quantities 
 
of grams; the new radioactive elements could be produced in the chain 
 
reaction in quantities corresponding to tons of radium equivalents. While 
 
the practical application would include the medical field, it would not be 
 
limited to it.
 
              A radioactive element gives a continuous release of energy for a 
 
certain period of time. The amount of energy which is released per unit 
 
weight of material may he very large, and therefore such elements might