1826.] Sir Jame$ Hall on the Consolidation of the Strata* 305 



source of an abundant supply of the elastic substance or fumi- 

 gator, whose action as a flux had been pointed out by the agglu* 

 tinations in Aikengaw above described. 



I conceived, that, if there w^ere at the bottom of the sea a 

 bed of sand and gravel, drenched with brine of full saturation, 

 and that heat were applied to it from beneath according to Dr. 

 Button's hypothesis, the first effect would be, to drive the water 

 from the lowest portion of the sand, and to convert the salt 

 which remained amongst it, together with the sand, into a dry 

 cake. During this operation, or until the cake became quite 

 dry, the absorption of latent heat would prevent the temperature 

 from surpassing the boiling point of brine. But no sooner was 

 this dryness accomplished, than, I imagined, the temperature of 

 the mass would begin to rise above that pitch ; the portion of it 

 next the fire would gradually acquire a red-heat ; that then the 

 salt, being made by the heat in part to assume an elastic form^ 

 would be sent in fumes through the dry cake just described, and 

 thus, by partially melting the contiguous particles, produce aa 

 agglutination. 



Such being my theoretical views, no time was lost in submit- 

 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 

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

 cific gravity, in the form of brine, I proceeded to make the fol- 

 lowing experiments. 



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

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

 throughout the experiment : the whole was then exposed to heat 

 from below. 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 pro- 

 duction 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 instance of this 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 all these cases, as a 

 New Series, vol. xii. x 



