OR SNAICE STONE. 



383 



Having obtained, from three different sources, several specimens of the 

 mineralvariety, for the distinction is familiar to those who sell these stones^ 

 I have thrown together the following particulars, the result of a cursory and 

 somewhat hasty examination of them. 



It is to be regretted that Dr. Davy omitted stating the specific gravity 

 of those he examined. The determination of the specific gravity affords one 

 of the easiest, and I may say most certain methods, of recognising substances 

 possessing any thing like definite composition. The importance of the cha- 

 racter for discrimination begins to be generally acknowledged, and it is from 

 a failure in noting this, and other equally obvious particulars, that many of our 

 published analyses cannot, with certainty, be referred to the substance operated 

 on. An examination of the specific gravity of the several specimens which 

 I possess of this production, has satisfied me, that more than one substance is 

 sold, and passess current as a mineral Bezoar. My collection contains at least 

 two marked varieties, which I shall endeavour to discriminate as follows. 



No. 1. Obtained through the kindness of G. W. Trail, Esq., Commis- 

 sioner in our Northern Mountains, from the people of Jowakir, who say that 

 it is found with detritus, in a cave or natural quarry, in the road, leading into 

 the valley of the Setlej. It is stated to be procurable in sufficient quantity. 

 These specimens offer the following characters. 



The specific gravity is 2-31, the hardness 3. It is in smooth flat 

 pieces of middling size, two and half inches by one. These have the 

 surface varied by conchoidal depressions, or hollows. Other pieces are of an 

 irregularly ellipsoidal figure, though I have since had reason to believe, that 

 these are, in reality, a distinct substance. The former are, externally, of an 

 olive green color, and have a waxy lustre, being polished by frequent attrition, 

 when worn, as they are used to be, round the neck as a charm. Internally, 



4 A 



