AGGREGATION. 161 



and that whenever a solid disappears, it passes 

 through the liquid state into vapour. 



So also, in the formation of new aggregations, 

 whether these be liquid or solid, or whether they 

 be what we call simple or what we call compound, 

 the primary state that in which the combina- 

 tion or the aggregation begins is the state of 

 air. It is of no consequence whether the result 

 be what we call a new body, or what we call the 

 repairing of an old one ; for the process of nature, 

 however it may vary in appearance, and whether 

 to our senses it be visible or invisible, is always 

 the same. Air with air is the only state of inti- 

 mate union which we know of union that is pri- 

 mary, or that of atom with atom, so that the 

 compound or the mass may, to our observation, 

 appear one substance. 



Liquidity is a weakening of the cohesion of par- 

 ticle with particle ; but it is not, in the case of 

 any liquid with which we are acquainted, a total 

 suspension of that cohesion. There is no liquid 

 but which can form into drops, or be poured in a 

 continued and connected stream, which shows 

 that the particles have still some attraction, as we 

 call it, for each other. They are not quite sub- 

 dued, but, like the bent bow, retain their capacity 

 of returning from the bend. Some, no doubt, 

 pass very soon into vapour. In dry air, single 

 drops of ether will evaporate before they reach 

 the ground from the usual height of the hand ; 

 and there are many instances of showers being 

 evaporated in their fall, and never reaching the 

 ground ; indeed, most showers are less or more 

 evaporated in their falling by the warm air near 

 the sheltered and low places ; and thus there falls 

 p 3 



