1826.} Sir James Hall on ike ConsolidatioU of the Sti'ata. 309: 



sand, and in which gold had melted in the brine experiment 

 just mentioned, now remained permanently black and cold ; 

 and the whole of the sand in the pot, when removed from the 

 furnace, fell out loose by its own weight j not the least trace of 

 consolidation having taken place. 



We may thus, I trust, presume to have added one more new 

 and important modifying circumstance of heat, to those already 

 advanced in support of the Huttonian doctrines ; for, since it 

 has been experimentally shown, that heat, under the modifica- 

 tions produced by the presence of salt, as above-described, is 

 fully adequate to the consolidation of loose materials, exposed 

 to its action, it may fairly be presumed, that salt has performed 

 a part, and a very important part, in the consolidation of the 

 strata of the globe. 



I should be doing injustice to the subject, were I not to state, 

 that, besides the views developed in the foregoing paper, and 

 supported by actual experiment, many others have occurred to 

 me, respecting the agency of salt under various modifications, 

 and all bearing more or less directly upon the Huttonian Theory 

 of the Earth. Some of these views have been submitted to the 

 test of experiment, and the results, as far as they have yet been 

 carried, give me great hopes of ultimate success. Others are 

 still in the shape of mere conjecture ; and none of them are yet 

 in a state to lay before the Society in detail. A simple allusion 

 to one or two of the most important of these views may probably 

 be received with indulgence ; and I shall be very happy if 

 gentlemen possessed of adequate leisure shall be induced to 

 follow up, by actual experiment, what I have thrown out as 

 mere matter of speculation. 



I conceive that salt, in the state of fumes, and urged by a 

 powerful heat, possibly also modified by pressure, or perhaps 

 combined with other substances, may have penetrated a great 

 variety of rocks, acting as a flux on some, as in basalt, granite, 

 &c. ; agglutinating others, as in the case of sandstone, pudding- 

 stone, &c. ; softening others, as in the case of contorted strata 

 of greywacke. In many cases, too, I conceive that these fumes 

 may have had the power of carrying along with them various 

 other materials, such as metals in a sublimed state, which would 

 in this way be introduced into rents, veins, and cavities, or may 

 even have entered into the solid mass of the rocks, which I 

 imagine these fumes may have had power to penetrate. I have 

 already tried some experiments in pursuit of these ideas. Salt, 

 for instance, has been mixed with oxide of iron, reduced to fine 

 powder^ and then exposed to heat along with quartzose sand. 

 The iron, I found, was borne up along with the salt fumes. The 

 sandstone, formed in this way, was deeply stained with iron, 

 and other most curious appearances presented themselves. 



Every one who has seen a sandstone quarry must have noticed 



