I885-J 
Action of Chemical Forces. 645 
in some respeCts resembles eleClric and magnetic attraction ; 
it is greater between two atoms when one is more strongly 
positive and the other more strongly negative. Cohesion, 
that is, the force which controls the distance separating 
atoms in the liquid and solid condition, resembles gravita- 
tion in not exercising this selective attraction, but differs 
from it in taking place only through small intervals of space. 
1 he same difference also distinguishes chemical aCtion 
proper from eleCtric and magnetic attraction. Although 
chemical aCtion proper and cohesion thus differ so widely, 
it is possible that the same causes which produce the one 
produce the other. For cohesion is greatest where the atom 
has the power of uniting with the greatest number of 
atoms of opposite character, and least where the atom is a 
monad. 
We can imagine that these two attractions are the results 
of the aCtion of elements of force, which we may call 
chemical poles. The pole is the immaterial counterpart of the 
atom. Each is minute, indivisible ; the atom is the unit of 
matter, the pole the unit of chemical force. A pole is indi- 
visible, and cannot coalesce with any other pole, although 
there can be mutual inductive action between them. This 
mutual aCtion resembles the induction which takes place 
between magnets and between electrified bodies. Poles 
differ in kind, being negative and positive, and chemical 
aCtion proper is the result of the attraction between pairs of 
poles, of opposite character, or at least of unequal intensity, 
each pole attracting only its fellow in the pair. Cohesion, 
on the other hand, is the result of the. general attractive 
aCtion of poles, the influence of each being diffused over all 
other poles within the range of its power. A monad atom 
is the locale of a single pole, which dominates it. A dyad 
atom is possessed of two poles, each of which aCts indivi- 
dually upon outside atoms, ar.d exerts an indueftive aCtion 
upon its fellow in the same atom. The inductive aCtion 
lessens the power of each pole, and hence chemical affinity 
is less intense than in the monad atom. In the same man- 
ner a triad atom is the seat of three poles, each less intense 
than either of the poles of the dyad atom in the same cycle. 
But the sum of the general diffusive attractions of the three 
poles is greater than the sum of the general diffusive attrac- 
tions of the two poles in the dyad ; therefore the atomic 
volume of the triad is less than the atomic volume of the 
dyad. And since the poles are links binding all adjacent 
atoms to one another, the resistance to the dissolving 
tendency of heat increases with the number of poles. A 
