712 Dr. N, Campbell and Prof. E. C. C. Baly on the 



can have no physical significance unless these quanta are 

 integral multiples of a fundamental unit. Dr. Campbell 

 speaks throughout of frequencies and the least common 

 multiple of these frequencies, and in conclusion he states 

 his opinion that there is no general belief in a fundamental 

 unit of frequency. I would point out that my theory is 

 based on the assumption that each elementary atom is 

 characterized not by a frequency but by its energy quantum, 

 the frequency being due to the time factor in the process 

 involving the absorption or emission of one quantum, 

 namely the shift of an electron from one stationary orbit to 

 another. To my mind the difficulty in postulating a 

 fundamental unit of energy is not so great as it might be in 

 postulating a natural indivisible unit of frequency, especially 

 when it is remembered that this fundamental unit is ex liypo- 

 thesi associated with matter. 



In my papers I made the assumption that two atoms in 

 combining together contribute each an equal share towards 

 the total energy loss and therefore emit an equal amount of 

 energy as whole numbers of their characteristic quanta. 

 This very simple hypothesis naturally means that each atom 

 evolves an amount of energy which is the L.C.M. of the 

 quanta characteristic of the two atoms, and in putting it 

 forward I was tacitly assuming that each elementary 

 quantum is an integral multiple of some fundamental unit. 

 I am very indebted to Dr. Campbell for pointing this out. 



The existence of this fundamental unit of energy asso- 

 ciated with matter does not seem to me to be difficult of 

 acceptance. Very possibly the fundamental unit is the 

 elementary quantum characteristic of the hydrogen atom, 

 the quanta characteristic of other atoms being integral 

 multiples of this. The very interesting possibility that 

 every atomic nucleus is built up of hydrogen nuclei certainly 

 does not increase the difficulty of belief in this, and in 

 addition I may refer to the statement in my paper that simple 

 arithmetical relations do seem to exist between the ele- 

 mentary quanta I have been able to calculate. 



Apart from the question of the correctness of any 

 particular theory, the non-existence of a fundamental unit of 

 energy would seem to lead to utterly chaotic and unco- 

 ordinated relations between the frequencies and energy 

 contents of substances. It would I think stultify all hopes 

 of quantitatively coordinating energy and chemical reaction, 

 and as is well-knowm many most promising results have 

 been obtained by Bodenstein, W. C. McC. Lewis, and others 

 in this direction. 



