222 PROPERTIES OF AIR 



ally refer to solids in general ; to solids whose 

 densities are altogether equal. The parti- 

 cles of which a mass of granite is com- 

 posed, with relation to each other, press as 

 much as they are pressed ; they resist, as 

 much as they are resisted ; and, therefore, vir- 

 tually, suffer no pressure; they subsist in a 

 state of equilibrium, or of balance. By being 

 incompressible in their nature, solids do not,, 

 because they cannot, suffer any compression. 

 The incompressibility of water, has been satis- 

 factorily proved, by the florentine experiment : 

 a volume of it was enclosed in a golden sphere, 

 and placed between two screws, and acted 

 upon by the most powerful agents : although 

 particles of the water issued through the gold, 

 and proved that it was porous ; it, nevertheless, 

 showed that water was incompressible ; and 

 that its bulk could not be diminished, by the 

 compressing force to which it was exposed.* 

 If liquids are in their nature incompressible, 



* It ought, however, to be mentioned, that as water has, 

 generally, a given quantity of air diffused in it, and which 

 is compressible to a great degree, so as to be reducible from 

 a large to a smaller volume ; that whenever the experiment 

 has been made, and an opposite effect produced, we ought 

 to conclude that the small diminution of bulk which has taken 

 place, has, most probably, arisen from the condensation of 

 the air, in consequence of the compression to which it has 

 been exposed, and not from the condensation of the water. 



