W. A. Norton — Variability of the Ultimate Molecule. 195 
envelopes may Es to reach their original distance from the 
central atom e dimensions of the m olecules, as a whole 
hea spas ess. e coéfficients n and m (eq. 1) should 
also be more or less altered, and thus the neutral distance x 
between the contiguous envelopes at which the effective force 
J becomes zero, should vary. From the combined operation of 
these two causes, the relative positions of equilibrium of the 
molecules should be more or less altered. a force of tension 
be applied to the body, a permanent change of an opposite 
character may ensue. 
It still remains to be seen how far the molecular theo 
that has been set forth, can be reconciled with chemical facts. 
This question opens too wide a field for present discussion even 
in the most cursory manner, but a word or two ought to be 
said to obviate the objection that may at once occur to the 
reader as fatal to the theory, viz: that the absolute invaria- 
bility of atoms is established by chemical facts. Strictly speak- 
ing, these facts only show the weight of the atoms to be inva- 
riable, and that they exhibit the same chemical properties 
whenever the relations to other atoms are the same, and 
certain cases (e. g. solution) over a certain range of variation in 
such relations; provided, also, the he ag of the physical 
agents on them is the same. But this does not preclude the 
supposition that large variations of their mechanical state may 
occur while the atoms are under different mechanical and phys- 
ical relations. It may be added that the received molecular 
formulas of substances would still remain the same, but would 
densation of the gaseous mixture. en two volumes 
of hydrogen are mixed with one Shank of oxygen, and by 
the pore: vig are made to combine, the mixed gase d 
ae would contain ae ultimate molecules (= chee cs ) 
