SIR JAMES HALL on the Consolidation of the Strata. 325 



Similar results, in all respects, were produced by exposing 

 pure pounded quartz to the action of the salt fumes, and also 

 when gravel, or any other mass of loose materials, was used in- 

 stead of sand. 



Having now shewn, in a satisfactory manner, that salt, whe- 

 ther in a dry state mixed along with loose materials, or driven 

 in fumes through them, or applied in the state of brine, and ex- 

 posed to heat, is a sufficient agent to produce a consolidation, 

 such as we see in natural sandstones and other stratified rocks, 

 it remains to be investigated, whether an adequate supply of 

 this flux may be reckoned upon in nature. 



It is well known that great diversity exists in the degree of 

 saturation of the sea by salt, at different places ; and BUFFON has 

 been at much pains in collecting examples of this diversity in 

 his geological volumes, introductory to his Natural History. It 

 is known that, in many of the communications between sea and 

 sea, a constant current sets one way, indicating that the evapo- 

 ration from the sea, to which this stream flows, surpasses in 

 quantity its supply of fresh-water from the rivers, rains, and 

 springs. This is remarkably the case with the Mediterranean, 

 into which a perpetual stream sets from the ocean, at the Gut of 

 Gibraltar. We have reason, then, to conclude, both that the sur- 

 face of the Mediterranean is lower than that of the ocean, and 

 likewise that the quantity of salt in the former is perpetually on 

 the increase ; so that the specific gravity of the waters, and the 

 intensity of their saturation, must be perpetually advancing to a 

 state of brine. I am well aware, that an attempt has been made 

 to render such a conclusion unnecessary, by the supposition of a 

 counter-current flowing at the bottom, out of this great basin ; 

 but such suppositions are, in my opinion, altogether gratuitous. 

 . What is here said of the Mediterranean, will apply no less to 

 other seas, and even to the great oceans. And wherever a basin 



