208 Sir A. Crichton on the [March, 



If the supposition be well founded, that granite and its asso- 

 ciates are of igneous origin, inasmuch as they are the result of 

 quick oxidation and fusion, there ought not to be any great con- 

 stancy in the super-position orjuxta-position of these rocks, for 

 it is clear that they may have varied according to the preponde- 

 rance of any one metal, or any number of metals, in any given 

 portion of the metallic nucleus. 



Other causes appear to have co-operated with this in produc- 

 ing a considerable variety in the mechanical aggregation of the 

 primitive rocks, as well as in their forms and relative position. 



In a paper expressly written on antediluvian temperature, it 

 cannot be expected that I should enter fully into an examination 

 of all these causes; yet a cursory view of some of them is una- 

 voidable for the elucidation of what is to follow. 



The immediate effect of the oxidating process of the metallic 

 mass would necessarily be a violent ebullition, agitation, and 

 evaporation, of the surrounding fluid, and also the formation of 

 various gases and gaseous oxides. Although the extinction of 

 the ignition would result as soon as a crust of earthy oxides (the 

 primitive rocks) was formed, yet during the consolidation of 

 these, the action of the watery vapour, included between the 

 intensely heated nucleus and the hot involucrum, would give an 

 elastic force to the included vapour commensurate with its heat. 

 When to this supposition is added the phenomena resulting from 

 causes which we have every reason to believe to be similar, such 

 as the sudden elevation of islands and of great tracts of land on 

 the coasts, as well as the equally sudden depression of other 

 tracts of continents, we are furnished with strong reasons for 

 believing that many parts of the imperfectly solid and still 

 heated granitic mass must have been elevated and rent in 

 various places, giving birth to groups and chains of granitic 

 mountains, the peaks of which, although greatly worn down 

 since that period, still exhibit a character of ruggedness and 

 rupture which peculiarly coincides with the theory. 



The following account of the highest granitic peak in the 

 Upper Oroonka district, taken from the justly celebrated Baron 

 Humbold's excellent work, entitled " Personal Narrative," is 

 appropriate to the present subject, and so singularly interesting 

 in itself, as to justify its insertion in this place. I may premise 

 that the granitic peak called Duida is estimated by this scientific 

 traveller at 1,300 toises above the level of the sea. 



" The granitic summit of Duida is so nearly perpendicular 

 that the Indians have vainly attempted the ascent. It is known 

 that mountains the least elevated are sometimes the most inac- 

 cessible. At the beginning and at the end of the rainy season, 

 small flames, which seem to change their place, are seen on the 

 top of Duida. This phenomenon, which it is difficult to doubt 

 on account of the agreement in the testimony concerning it, has 



