Evolution and Devolution of the Elements, 41 
not direct evolution products of copper. In support of: our 
view that the individual members o£ these three groups are 
not connected by a process of direct evolution, we would also 
mention that the three elements zinc, cadmium, and mercury 
have been shown by Cuthbertson and Metcalfe * not to be 
connected in their refractivifcies. 
A remarkable result has recently been obtained by J. J. 
Thomson f, which is entirely in agreement with the theory 
of evolution as set forth above. He has found that the number 
of corpuscles in an atom approximates to the atomic weight. 
Thus in the atom of hydrogen there is 1 corpuscle, and in a 
molecule of air there are 25-28. Now, with our hydrogen 
is associated 1 electron, with nitrogen 8 4-5 = 13 and oxygen 
8 + 6 = 14, which would give about 27 to 1 molecule of air. 
Can it be these free electrons which have been measured ? 
The objection to the result is that there are many more lines 
in the arc spectrum of iron which give the Zeeman effect, 
than there would be electrons. However, when subjected to 
the great strain of the electric arc, it is highly probable that 
some of the corpuscles from the outer ring of the atom are 
set into vibration, as well as the electrons, and this would 
afford an explanation of the number of lines. 
However, to return to our main subject. We have traced 
the growth of all the elements, and will now proceed to 
discuss the relations of their properties. 
Firstly, members of the same family are formed from the 
same protons, and have the same shaped rings. Hence there 
must be a very close relationship in all their properties, as is 
the case in groups 1, 2, 3, and 8, where the structure is 
perfectly regular. Groups 5, 6, and 7 are also very similar ; 
but the first members differ somewhat from the others, because 
the first ring is situated round one of different valency, or shape. 
Again, on the outer ring will depend a certain number of 
properties. Two elements with the same outer ring will show 
several similarities. Their spectra will probably be of the 
same type, and their valencies being the same, they will form 
similar compounds. 
Now Rudorf % obtained certain relations between frequency 
differences of pairs of lines in the spectrum of an element 
and its atomic weight. On plotting the values of d/A 2 against 
those of A, where d is the frequency difference for an element 
of atomic weight A, he obtained characteristic curves for each 
family ; moreover, the point representing sodium was at the 
intersection of the curves through K, Cs, Rb. and Cu, Ag, Au. 
* Loc. cit. 
t Phil. Mag. vol. xi. p. 7G9 (June 1906). 
X Zeits. Phys. Chem. vol. 50. p. 100 (1904). 
