Evolution and Devolution of the Elements. 35 
sets of eight electrons takes place, but only two electrons are 
taken up by the outer ring of the antecedent element, with 
the result that a distorted ring is produced of valency six. 
In the case of the element fluorine we have a distorted 
ring of valency seven produced in exactly analogous fashion. 
We would point out that from this point of view a trivalent 
element can only give rise to four indirect derivatives, and 
all of these possible derivatives are accounted for in our 
Table. 
The next case we have to consider is that of the element 
silicon. This is a tetravalent element, and consequently can 
only give rise to three indirect derivatives, viz., a penta- 
valent, a hexavalent, and a heptavalent element. Thus from 
silicon we have the direct derivative titanium, this being the 
case when the superadded ring gives up four electrons to 
complete the system with the four already existing electrons 
on the four-membered ring of silicon. 
We then have the first indirect derivative in which a 
distorted ring is produced of valency 5, when only three 
electrons are transferred. This is the case with the element 
vanadium. We have the third and fourth indirect derivatives 
chromium and manganese wdrich possess distorted rings of 
six and seven valencies respectively. 
Now each of those elements which has been produced by 
a process of indirect evolution such as we have described, 
may itself become the source of new elements and families 
of elements produced from it by normal or direct processes 
of evolution. Thus the elements nitrogen, oxygen, and 
fluorine will give rise to families of pentavalent, hexavalent, 
and heptavalent elements respectively. 
The three indirect derivatives of silicon, viz., vanadium, 
chromium, and manganese, are penta-, hexa-, and heptavalent, 
but they differ very considerably from the three elements 
nitrogen, oxygen, and fluorine, which have the same valencies. 
The three first mentioned elements are electro-positive, that 
is to say, the electrons in each case exhibit comparatively 
little desire to complete their systems of eight. This is an 
abnormal condition, and one that it is difficult to find any 
reason for. It may be owing to the fact that these elements 
have been produced by two indirect processes of evolution, 
or it may be owing to the size of the outer rings. That the 
three elements, vanadium, chromium, and manganese have 
practically no desire to complete their sets of eight is 
evidenced by the fact that they do not form any compounds 
with hydrogen or with any other electro-positive element. 
Although thev are pentavalent, hexavalent, and heptavalent 
D2 
