218 OCCURRENCE OF GYPSUM IN THE 



newest floetz rocks, and that it is a merely local occurrence. This opinion 

 I derive from the very limited quantity in which it is found, from its being 

 associated with a sulphuretted lime-stone, and lastly, from its containing 

 fragments of the neighbouring rock. 



4. The principal deposit occurs in the bed of a stream which leaves 

 the hills immediately below the village of Nagal, in the Dehra Dun — ■ 

 This stream, so well known to visitors who come here from the Haridwar 

 fair, as deriving its name from a spot called Sansar Dhdrd, * or the 

 dripping rock. This is a perpendicular bank of fifty feet in height, which, 

 for a breadth of sixty or seventy feet, is faced with pendent stalactites, 

 from which, and from the brow of the hill, descends a continual shower 

 of drops. The water contains carbonate of lime in solution, (probably 

 through the medium of carbonic acid) and is continually depositing it, so 

 as to add to the number as well as size of the stalactites. 



5. Two miles beyond this spot, at the confluence of another stream 

 which comes from the left, the water of which is also charged with car- 

 bonate of lime, is seen the gypsum associated with a rock of rather an 

 anomalous character. It has all the aspect of a lime-stone, but refuses 

 to effervesce with acids, or at least does so very feebly. It is frequently 

 of a deep black color and fetid odor, particularly when struck or fractured. 

 The odor is that of sulphuretted hydrogen. As it passes into well cha- 

 racterised lime-stone, it must be considered, geologically, as one of the 

 numerous types of that rock, though, as it is so highly charged with 

 argillaceous, and probably siliceous matter, its claim to the title of a 

 lime-stone would not be so obvious in a hard specimen, it is one of an 



extensive 



* Or, according to some authorities, Sastar Dhdrd. 



