. TRANSACTIONS OF THE SECTIONS. 51 
this is the peculiar feature in his new theory of physics; and all the varieties of 
atoms arise from differences in their absolute forces and the extent of their spheres 
of repulsion, Deductions from this theory agree with experiment and observation. 
From this theory he has deduced the alternate spheres of force observed by Newton 
with electrical attraction and repulsion, not as peculiar forces, but as circumstances 
dependent on the combinations of the classes of atoms mentioned below, and the 
following laws of chemical combination, viz.—Law I. That two atoms, simple or 
compound, combine one with one without the intervention of a third, and that the 
volume remains unaltered, or is contracted one half. Law II. Two atoms combine 
by the intervention of a third, and the volume remains the same as that of the two 
combined atoms, or is reduced exactly one half. These laws he has examined in 
about one hundred cases, in which he finds them confirmed by experiment without 
exception. 
In order to explain these laws, he takes what is presented by many phenomena, 
that there are three classes of atoms.—Class I. Such as have comparatively a small 
sphere of repulsion and a great absolute force; such are the common elements of 
chemists ; hydrogen, nitrogen, carbon, &c. Class II. Such as have a large sphere 
of repulsion and a small absolute force ; these he is persuaded constitute the electric 
fluid. Class III. Such as have a very large sphere of repulsion and a very small 
absolute force, which, when in motion, as it seems to him, constitute caloric, light 
and actinic rays, one or other, according to their velocity. 
Now if into a vessel containing atoms of the second and third classes under com- 
pression there be introduced a considerable number of those of the first class, each 
of these will become a supporting centre against the reaction of the-other classes : 
it is evident that these centres will be uniformly disposed, and that their distances 
will be equal to the distances between the atoms of the interior surface of the vessel 
and the adjacent atoms of the gas, and the pressure between the atoms will increase 
with the number of these, considered as supporting centres; hence under a given 
pressure the volume will depend on the number of supporting centres. Thus if the 
same number of atoms of nitrogen be substituted for the hydrogen, the volume will 
not be altered, although the nitrogen is fourteen times heavier than hydrogen ; it will 
be still the same if we have the same volume of chlorine, which is thirty-six times 
heavier than hydrogen. The same observations apply to iodine, bromine, &c. and 
to oxygen, taking its atomic weight at sixteen; thus we find that the volume depends 
not on the absolute force and sphere of repulsion of the atoms, but on the number 
| of supporting centres. 
The same holds good in compound atoms; thus, muriatie acid is H.*.Cl, nitric 
oxide O.*. N,; carbonic oxide O.:. C, which are instances of the first law where the 
yolume remains unaltered, and this doubtless takes place when the electric matter 
collects between the combining atoms; thus light acting on a mixture of hydrogen 
and chlorine causes the electric fluid to collect between them; hence the number of 
supporting centres remains the same, and the distance between the atoms of hydrogen 
and chlorine is unaltered; which holds good in the other examples, and all similarly 
combined. Examples where the volume is contracted one half are, cyanogen N C, 
E. Davy’s carburet of hydrogen HC, &c.; here the electric fluid collects on the 
exterior sides. 
As illustrations of the second law take water vapour H(O)H, carbonic acid 
O(G)O, alcohol H, C(H,0)CH,, zxther vapour H,C,(H, O)C, Hy, enanthic ether 
Hy Co(Hy¢ C4 Oo, HJO)C, Hy, ethal Hyg Cy(Hz O)C3 Hyg, &c., in which and all such 
the volume is the same as that of the extremes, where the connecting atom makes no 
part of the volume, being protected and prevented from becoming a supporting cen- 
tre by the intervening electric fluid, which produces the combination ; thus, for in- 
stance, in cenanthic ether, the forty-five atoms of cenanthic acid do not alter the 
distance of the etherine H,C:, H,C, and the same in all such cases, where the 
volume is the same. As examples, where the volume is reduced exactly onc-half, 
we have olefiant gas HCH, nitrous acid ONO, benzin or Dr. Faraday’s carburet of 
hydrogen HC, HC, HC, where the extremes connected by the intermediate atom 
ate reduced to one centre of support, the electric fluid collecting on the exterior sides ; 
sulphur vapour is analogous to benzin, being S, S, S reduced to one centre of sup- 
port. In all cases where the specific gravity of the gas is found, these laws of com. 
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