260 Proceedings of the Royal Society of Edinburgh. [Sess. 
In like manner as to the acids of these glycols ; oxalic acid, for instance, may be 
C'-'O-OH 
: •••O 2 
represented as 
C ' " o 2 
• ■ 0 • " OH 
Respecting these acids, it may perhaps be allowable to suggest the possibility of 
the molecule having two poles, and that especially the atom of oxygen situated at 
one or perhaps both, and near to two atoms of oxygen bound together, and forming 
no secondary combinate, may be in a state presenting great affinity for basic oxygen. 
Analogy with electric poles may perhaps demand the opinion that all the negative 
oxygen be situated upon one side of the molecule. It will in that case be preferable 
C”"0 2 
: —O 2 
to represent the oxalic acid as 
C . 0 
OH 
Be that as it may, however, the rational 
0 OH 
method of investigation proves it to be a law, that in acids of the type nCM 4 the 
presence of two atoms of oxygen bound together so as to form only a primary part 
of the same molecule, and situated close to the negative oxygen, is necessary to the 
calling forth or production of this negative state. 
This is a particular instance, but it moreover shores generally how the electro- 
positive or the electro-negative value of the elements mutually modify and condition the 
electropositive or electronegative value of each other when in combination. 
This law is different from the electric hypothesis which chemists have formerly 
defended, but which never could be traced throughout a thoroughgoing application 
of their views to organic chemistry. 
The law here distinctly enounced coincides exactly with, and is rendered 
apparent by the application of the theory of chemical combination which I support. 
