1 835.] Geology of the Bombay Islands. 333 



probability of any remnant continuing, had not the fore- 

 sight of the honourable governors of the country obviated 

 the latter cause in some measure, by stationing a resident 

 sergeant to guard these interesting relics. The rock, when 

 first exposed, is highly indurated, and difficult either to 

 fracture or polish, both of which circumstances add greatly 

 to the wonder and admiration with which we must view the 

 temple and sculptures. 



In geological investigations, not the least interesting 

 inquiry consists in observations with regard to the degra- 

 dation of the rocky masses, and the formation of the soils 

 for the growth of the members of the vegetable kingdom. 

 Such questions, it is obvious, can be most satisfactorily 

 solved on insulated lands, where no agencies save the pure 

 natural causes can come into operation. Coral islands, 

 which are of such recent formation, present the most simple 

 illustration upon this point, where we find the calcareous 

 masses splitting under the action of the sun's rays, crum- 

 bling and affording a scanty soil for foreign seeds floated 

 by currents to take root, and thus to extend the formation 

 of the soil, by the loosening power of their roots and the fall 

 of their leaves.* 



The heat of the sun alone may be considered, therefore, 

 a powerful auxiliary in the production of soils, and this 

 influence is especially applicable to the Indian climate, where 

 the dark hue of the rocks greatly favours the imbibition 

 of heat ; an observation similar to that which was made by 

 Link, with regard to the black slates of Pezo,f and subse- 

 quently by Humboldt, was demonstrated in reference to the 

 black bare rocks on the banks of the Oroonoko, whose 

 temperatures were found to be elevated during the day 

 34|° F., and during the night 18° above that of the atmos- 

 phere .% In India, at the termination of the rains in Sep- 

 tember, the porous stony masses must of course be satu- 

 rated with moisture, and when the rays of the sun excite 



* Dr.R. Forster has well described the structure and mode of formation of coral 

 islands, in Cook's Voyage, of whose accuracy the present writer had ample proofs, 

 while examining similar deposits on the coast of Sumatra. A fuller, but not more 

 distinct account of coral islands is detailed in Beechy's Voyage. 



t Link's Travels in Portugal, 8vo. 1801, p. 64. 



% Humboldt's Pers. Nar. vol. v. pt. i. 26. 



