60 On FUiiditif, and 



pressure, be so distributed in the sphere, as that the density 

 and consequent weight of the compressed gaseous fluid at the 

 centre of the sphere, and to a certain extent around, will be 

 greater than of the liquid, in a like position within the globe 

 before-mentioned. It would be capable then of sustaining, in a 

 liquid form, water introduced into it. 



Let those suppositions be combined ; and a ball be next ima- 

 gined, composed of a gaseous fluid, and of a liquid, with solids 

 interspersed. It is easy to conceive the relative compressibility of 

 those substances, and the actual compression of them, to be 

 such, that the interior portion around the centre may be occu- 

 pied by highly condensed gas ; encompassed by a liquid mass, 

 which is pervaded by a gaseous fluid, both decreasing in density 

 upwards ; and beyond the liquid surface, surrounded by an 

 atmosphere consisting of gas, penetrated by aqueous vapour. 



Solid substances, sparingly scattered in such a fluid ball, 

 would float at a great depth : but the magnitude of cohesive 

 masses, and the abundance of them, may be imagined such that 

 they may be fast locked and fixed together, in the manner of 

 field-ice ; at the same time that the weight of them is such, as 

 would float them, were they loose, like an iceberg, with a rela- 

 tively small portion of the floating mass emergent. 



In a word, a solid crust might exist, sustained by the water 

 in which it is immersed, at the same time that the irregular and 

 uneven surface of the cohesive mass emerges in part, while 

 other portions are submerged. 



It may be asked, whether the hypothesis here adverted to is 

 opposed by any such conclusive objections, as to be altogether 

 undeserving of consideration? And after remembering that 

 water is permeable to air, and, when exposed to it, absorbs a 

 saturating portion of it ; and that air is more compressible than 

 water, and water more so than solids; is it not, in truth, con- 

 ceivable that the earth's structure may be no other than has 

 been hypothetically put? and might not a theoretical geologist 

 erect, upon some such basis better sustained by correct inductive 

 results, as to the relative compressibility of air, water and 

 commonest solids, a buoyant theory, to account for the seeming 

 intrusion of substances from beneath into superior masses, and 



