6 Wilde, JA;////V Weights, A' eon and Helium. 



gravities at ordinary temperatures) has induced me to 

 review the multiple relations of the series of elements 

 H/;^ with the following results : — 



1. Ne 7 + Ar 21= 28f2 = N 14 



2. Ne 7 + Si 35= 42^2 = Ar 21 



3. Ar2i+Xe 63= 84^2 = Kr 42 



4. N 14-l-Fe 56= 70-f2 = Si 35 



5. Ne 7 + Pd 105 = 1 12-^2 = Fe 56 



6. N 14+ Au i96 = 2io^2 = Pd 105 



7. Ne 7x28 =Aui96 



8. Ne 7X 9 ^Xq 6}, 



An examination of the above Table shows (i) that 

 no less than six triads are formed in the series, in which 

 the sum of the atomic weights of the extreme members 

 is double the atomic weight of the means, and are all 

 multiples of Ne7. Triads of atomic weights have been 

 fully recognized b}- Dumas, Faradaj-, and other philo- 

 sophical chemists as indubitable evidence of community 

 of origin, of transmutation, and important factors in the 

 classification of elementary substances. (2) That the 

 atomic weight of silicon (35) follows naturally in the 

 series, and the lesser values Si 21, and Si 28, find no place 

 in the tabic. (3) That if the atomic weights of Ne, Ar, 

 Kr, Xe, were doubled, it would be necessary to double 

 those of N, Si, Fe, Pd, Au, and other members of the 

 series, which is obviously absurd. 



As the four new elementary gases have no chemical 

 properties their specific gravities are necessarily substi- 

 tuted for atomic weights. The experimental determi- 

 nation of their respective densities differ slightly from my 

 table owing to the difficulty of separation from each other, 

 probably from other causes which it is unnecessary on this 

 occasion to indicate. In the interests of science, however, 



