20 Prof. E. C. C. Baly on 



shown to be possible to calculate the energy evolved in the 

 actual combination to form the freshly-synthesized molecule, 

 we are now in the position to evaluate the total energy 

 evolved when atoms combine to give molecules as they exist 

 under the ordinary conditions of experiment. 



Let the case be considered of the combination of atoms of 

 different elements, and, further, let the characteristic fre- 

 quencies of these atoms be 9 x 10 10 , 1*2 x 10 11 , 1-5 x 10 11 , 

 and 2*1 X 10 11 , respectively. The least common multiple of 

 these four frequencies is 1*26 x 10 13 , and this, therefore, will 

 be the true molecular frequency of the resulting molecule.. 

 On the assumption made in the preceding paper that an 

 equal amount of energy is contributed for each atomic 

 frequency, the smallest equal amount evolved for each atomic 

 frequency' is 1*26 x 6*56 x 10" H or 8*2656 X 10~ 14 erg. The 

 total quantity of energy evolved, therefore, in the actual 

 formation of each molecule will be 4 x 8*2656 X 10~ 14 or 

 3*30624 x 10~ 13 erg, which will result in the establishment, 

 of the infra-red fundamental 5*04 x 10 13 . Since one quantum 

 at this frequency equals the sum total of energy evolved,, 

 the absorption of one energy quantum at this frequency 

 will result in the molecule just being resolved back again 

 into its atoms. 



The next stage in the process will be the formation of the 

 molecular force field, and let this be accompanied by the 

 loss of 20 quanta at the infra- red fundamental 5*04 x 10 13 » 

 As shown above, the molecular system will now be endowed 

 with an additional characteristic frequency, 5*04x21xl0 13 

 or 1*0584 x 10 15 , which lies in the ultra-violet region of the 

 spectrum. The energy lost by each molecule during the 

 condensation of its force field will be 5*04 x 20 X 6*56 x 10 _H 

 or 6*61248 x 10 ~ 12 erg. The total energy therefore evolved 

 in the two processes is the sum of 3*30624 x 10~ 13 erg 

 evolved in the combination of the atoms and 6*61248 x 10 -12 " 

 erg evolved during the condensation to form the molecular 

 force field, which amounts to 6*943104 x 10" 12 erg. This 

 amount of energy, however, is equal to one quantum at the 

 frequency 1*0584 x 10 15 , which is characteristic of the mole- 

 cular phase. As this is obviously true whatever may have 

 been the number of quanta at the infra-red fundamental 

 lost during the formation of the molecular force field, the 

 general conclusion is reached that one energy quantum 

 measured at the largest frequency characteristic of the 

 molecule is just sufficient to resolve that molecule into its 

 atoms. This is a general conclusion which includes Einstein's 

 photochemical law. 



