322 SIR JAMES HALL on the Consolidation of the Strata. 



ting them to the test of experiment. Taking it for granted that 

 a quantity of sea-salt must frequently be formed and deposited, 

 along with sand and gravel, at the bottom of the ocean (in the 

 manner I shall have occasion to describe at another stage of this 



O 



paper), where the water has been collected by its superior speci- 

 fic gravity, in the form of brine, I proceeded to make the follow- 

 ing experiments. 



Dry salt was placed along with sand, sometimes in a separate 

 layer, at the bottom of the crucible, and sometimes mixed through- 

 out the experiment : the whole was then exposed to heat from be- 

 low. I found that the salt was invariably sent in fumes through 

 the loose mass, and by its action produced solid stone in a manner 

 completely satisfactory, as illustrative of the facts in Aikengaw ; 

 and so as to give a good explanation of the production of sand- 

 stone in general. 



These artificial stones are of various degrees of durability and 

 hardness ; some of them do not stand exposure to the elements, 

 and crumble when immersed in water ; some resist exposure for 

 years ; others are so soft as not to preserve their form for any 

 length of time ; while some bear to be dressed by the chisel ; 

 and, it may be remarked generally, that, as far as the results of 

 my experiments have been compared with natural sandstone, 

 the same boundless variety exists in both cases. A striking in- 

 stance of tlu's resemblance occurs in the case of the Salt-Heugh, 

 the sandstone of which, when immersed in water, crumbles down, 

 exactly in the same manner as those results of my experiments 

 which taste much of salt. 



The fumes of the salt, no doubt, act, in ah 1 these cases, as a 

 flux on the siliceous matter, and thus cement the adjacent par- 

 ticles together. The Society are, doubtless, well aware of the 

 power of salt fumes in glazing pottery ; and the analogy, I con- 

 ceive, is complete. It is the application alone that is new. 



So far the results were satisfactory. But it next occurred, 

 that it might be plausibly objected, that the presence of the su- 

 perincumbent cool ocean, would interfere with the process, on 



