450 On the two great powers, (Serer. 
contiguous attraction is supposed to extend do in reality lead to an op- 
posite conclusion. 
Of an attraction between gaseous atoms, both similar and dissimilar, 
we shall have further satisfactory proof by the consideratiou of the 
following phenomena. In the transition of aqueous vapour to the 
solid state, a number of particles, which must have occupied a con- 
siderable space, convene to form a flake of snow. ) 
This must surely have been produced by a general attraction 
throughout all the particles of that portion of vapour, the attraction 
between the contiguous particles being doubtless the most powerful. 
Hence each minute crystal of the flake is formed by the affinity of se- 
veral neighbouring particles, but the aggregation of all the crystals to 
form the mass must be the product of an universal attraction of all the 
particles of the vapour. Otherwise no flake would be formed, but each 
grain would be precipitated separately. This instance alone appears a 
conclusive proof. Between dissimilar particles there are many like 
instances. The deliquescence of a salt has been adduced by NewrTon 
himself in proof of its attraction ‘‘ acting at a distance’’ on the parti- 
cles of vapour in the air, 
The mutual action of the particles of different gases on each other is 
often evident at considerable distances, as when two gases combine to 
form a solid or liquid, such as the muriatic acid and ammoniacal gases, 
‘and many others. 
If all these arguments and facts be admitted as true, sufficient has 
been said to prove that the attraction of atoms, whether of similar or 
dissimilar atoms, is not merely a contiguous force ; and as we have had 
evidence of its being exerted by all atoms in a gaseous state, but have 
no proof of its ceasing at any point, it must surely be considered as a 
power that operates, though weakly, at a distance, and that it does not 
-suddenly cease any where. 
Qndly. How far the attraction of atoms is general, i. e. whether all 
atoms in nature attract and are attracted by all, or whether attraction 
between atoms, chemical and cohesive, is confined to a limited num- 
ber. 
It would seem to be the opinion of most modern philosophers, that 
all homogeneous atoms exert a mutual attraction when sufficiently near 
to each other, and hence that the particles of gases would cohere if 
brought within the limits of their attraction. That all homogeneous 
atoms attract each other, there is not any reason for doubting. It has 
been above shewn that we have no proof of a limit to the distance at 
which attraction may be exerted, and that even in the gaseous state 
