^66 Mr Hardie on the Geology of the 



northern extremity of the lake, which, rushing in cascades 

 through a rocky and precipitous ravine, joins the small river 

 Bedus. This stream (Nullah)^ rising high in the hills to the 

 northward, flows, Hke the other streams of the valley, into the 

 Oodisagor. In fact, the whole of the Valley of Oodipoor might, 

 with no great difficulty, be converted into a large inland lake, 

 studded with numerous islands, now appearing in the form of 

 insulated hills. To effect this, little more would be necessary 

 than to raise somewhat higher the bund of the Oodisagor, and 

 to block up the narrow chasm which now gives issue to the 

 Bedus at the same point ; and there are many facts connected with 

 its geology, which seem to indicate that in such a condition it at 

 one time existed. The value of these facts will be better appre- 

 ciated when we have described the rock-formations of the valley, 

 and the geological phenomena which attend their occurrence. 



The more elevated portions of the Valley of Oodipoor, and 

 the rounded coUines which diversify its surface, are barren and 

 unproductive. The soil in such situations is exceedingly scanty, 

 and, during the greater portion of the year, is utterly destitute 

 of vegetation. The low lands, however, are covered with a rich 

 and luxuriant mould, and the cultivator has every advantage 

 which an abundant supply of water, and the greatest facilities for 

 irrigation, can afford. The cultivated land is, in consequence, 

 productive to an amazing degree. The soil is obviously derived 

 from the disintegration of the neighbouring rocks, and no ap- 

 pearance of the older alluvial deposits can be traced. The only 

 shells found belong to recent genera, such as still exist in the 

 lakes and streams. These sometimes present themselves in con- 

 siderable abundance in the soils : remains of Uniones and Plan- 

 orbes are by far the most numerous. 



A saline efflorescence sometimes appears on the surface of the 

 soil in the valley. On the plains of Mewar, in the Ajmeer and 

 Jeypoor districts, and indeed throughout the whole of Raj poo- 

 tana, a similar efflorescence is constantly observed covering the 

 surface, and occupying the dried-up beds of marshes and nullah 

 courses, in appearance exactly like hoar frost. This efflorescence 

 is called by the natives Reh^ and is used by them in the manu- 

 facture of soap, as well as in the preparation of an impure sul- 

 phate of soda, and other saline compounds employed by them 



