Sir James Hall on the Consolidation of the Strata. 5 



ed this, by suggesting that the pressure of the superincumbent 

 ocean was sufficient to confine the carbonic acid, and to cause 

 it to act as a flux on the quicklime. This theory, however 

 ingenious, was so abundantly gratuitous, that it by no means 

 satisfied even his own disciples. During his lifetime he dis- 

 couraged the experimental investigation of the subject ; but 

 no sooner was all delicacy on the subject at an end by Dr 

 Hutton's death, than Sir James Hall commenced a series of 

 experiments, which in the end set the question completely at 

 rest. He ascertained, by numerous experiments, that carbo- 

 nate of lime might readily be fused when exposed to heat, if it 

 were at the same time under a pressure not greater than Dr 

 Hutton's Theory required, or about a mile and a half of sea. 

 These experiments, in which the subject is treated in a very 

 masterly way, will be found in the sixth volume of the Edin- 

 burgh Transactions. In the words of Mr Playfair, it may be 

 truly said of them, "that, independently of all theory, they have 

 narrowed the circle of prejudice and error." 



So far Sir James had confined himself to the illustration 

 of doctrines purely Huttonian ; but we should be doing 

 injustice to his sagacity and originality, were we to omit 

 stating that he by no means followed Dr Hutton in all 

 his ideas. On the contrary, he always considered Dr Hut- 

 ton's explanation of the formation of valleys, and of the pre- 

 sent appearance of the earth's surface generally, as quite 

 incomplete. To account for these by the diurnal action 

 of the elements, he thought altogether untenable. Sir 

 James's theory, which is at once bold and original, is 

 published in the Edinburgh Transactions for 1812, vol. vii. 

 p. 139, 169, in two papers " on the Revolutions of the Earth's 

 Surface," to which we call the attention of our readers. Val- 

 leys he conceives to have been formed at various times by a 

 succession of heaves from below, which could not fail to rend 

 and dislocate the solid crust of the globe in a thousand 

 shapes, and to leave it as to the general features, in the rug- 

 ged and irregular form it at present retains, an appearance 

 totally inexplicable upon any view of diurnal action. But as 

 it must be admitted that most mountains, valleys, plains, 

 lakes, and other parts of the earth's surface, are evidently 



