24> Fictitious Vegetable Impressions in Sandstone Rocks. 



Before concluding, I may advert to another peculiarity I 

 have observed in the action of water when falling as rain upon 

 masses of earth exposed to it. This is the division of 

 the surface into a series of regular prismatic columns, occa- 

 sionally so perfect, as to represent a mimic Giant's Causeway, 

 and shewing a curious analogy between the action of fire 

 and water, the two great antagonist, but co-operative forces 

 in the dynamics of Geology. This prismatic arrangement I 

 have observed only on a very small scale, in different spots 

 in the neighbourhood of Mussoorie, and in some of the sec- 

 tions in the nullah's beds in the plains, and attribute its ex- 

 istence to the varying tenacity of the surface soil, parts of 

 which yielding sooner than others to the action of the rain, 

 afford greater facilities for its erosive power to operate, An 

 impression exists on my mind, that I have seen the same 

 sort of structure, but on a much larger scale in the district 

 around Bangalore, in the Mysore country, but having made 

 no written record of the circumstance, I cannot speak posi- 

 tively. Perhaps, Captain Campbell, whose observations on 

 these localities are as minute and careful in detail, as they 

 are interesting and important in general results, may be able 

 to supply some information on the point to which I have 

 alluded. 



have always been regarded as mineral rather than organic characters. 

 The cause of these singular and beautiful characters in rocks is still, 

 however, an unsettled point in which the observations of Lieut. Smith 

 must have considerable influence. — Ed. 



