200 CHEMICAL ATTRACTION. 



of resin, charcoal, and hundreds of other bodies, 

 are reduced to the state of an impalpable powder, 

 like the dust of our roads after a long drought, 

 they have little or no attraction for each other : 

 but if they be brought into contact with the 

 above volatile liquids, they cohere with consider- 

 able force. Why ? Undoubtedly because there 

 is a mutual attraction between the liquids and 

 powders, which counteracts the repulsive force 

 of the liquids, and prevents them from flying oft' 

 in the form of vapour. 



If the particles of dust had no cohesion for 

 each other whatever, they would represent the 

 condition of ultimate atoms wholly deprived of 

 caloric, which could neither approximate nor 

 recede from each other. At the temperature of 

 67 F. water is an elastic fluid in vacua ; but if 

 a thin film of water be placed between two 

 plates of glass in an exhausted receiver, they 

 cohere together, because the water is more strongly 

 attracted by the glass, than repelled by its own 

 particles. However imperfect such illustrations 

 may be, they are sufficient to prove that a self- 

 repulsive agent may become a bond of attraction 

 to other bodies. But the fact which must for 

 ever set this question at rest is, that the attraction 

 of all bodies for caloric augments, cceleris paribus, 

 in proportion as they are deprived of it, and that 

 their cohesion augments in the same ratio. 



To those philosophers who have regarded elec- 



