320 Prof. W. P. Harkins on the 



The most extensive collection of quantitative analyses of 

 meteorites has been gathered by Farrington, who has obtained 

 results for 318 iron and 125 stone, or 443 meteorites in all. 

 The data show that in these the six most abundant elements 

 are iron, oxygen, silicon, nickel, magnesium, and sulphur. 

 Not only is every one of these an element of even atomic 

 number, but they also make up 97'89 per cent, of the entire 

 number of atoms in the 443 meteorites, while the other even 

 numbered elements increase this percentage to 98"57, leaving 

 only 1*43 per cent, of elements of odd nuclear charge, so 

 only about one atom in seventy has an odd numbered positive 

 charge* or P — N is almost always an even number. Thus 

 while the number of negative nuclear electrons (X) is almost 

 always even, the value of P — X is still more often even, 

 which indicates that oddness of J¥, when it does occur, is 

 almost always an accompaniment of an odd value of P; so 

 almost no atoms belong to Class IV. in which X is odd when 

 P is even. Thus an odd value of P may occur whether N is 

 even or odd, though P is usually even when X is even, 

 or the tendency of X to be even may be said to be greater 

 than that of P. An hypothesis as to the cause of this 

 peculiar numerical relation will be presented later in the 

 section dealing with the groups, such as the alpha particle, 

 from which the more complex nuclei seem to be built. It 

 may be noted that in the alpha particle both X and P are 

 even numbers, the former equal to 2 and the latter to 4. 



If we now return to the consideration of the individual 

 atomic species, -whose abundance is represented in figs. 2 

 and 3 (PI. XII.), it is seen that nearly all of the high 

 peaks represent, as in fig. 4, species for which P — X is 

 an even number, especially for isotopic numbers and 4, 

 which include nearly all of the abundant species. The same 

 is true of isotopic number 2 in so far as the very few data 

 which are existent are concerned. On the other hand, there 

 seem to be more peaks of odd than of even atomic number 

 when the isotopic number is odd, this being the general rule 

 except that Mgj 25 and Six 29 are slightly more abundant in 

 the meteorites than corresponds to this relation. 



Nucleab Instability as Related to ax Odd Numbeb of 

 Negative Electrons in the Nucleus. 



The data presented in Tables III. and IV. show conclu- 

 sively that atoms which contain an odd number of nuclear 

 neo-ative electrons are relatively rare as compared with 

 those in which this number is even. In order to give 



