M. Duvaucel on the Great Cavern of Boobon. 51 



and hence infers, that, in the bi sulphate of the protoxide and 

 peroxide of iron, the ratio of the oxygen in the water and in 

 the base is that of three to one. For the rest he considers 

 every thing, except that of salt of iron, as foreign to the mix- 

 ture, even the sulphate of magnesia, which amounts to from 

 1 7 to 27 per cent. 



One of the minerals occurring along with botryogene is a 

 bright sulphur or lemon-yellow crystalline powder, which I 

 suppose to be the persulphate of iron with excess of base, men- 

 tioned by Berzelius. A similar mineral, also in the shape of 

 a yellow crystalline powder, is found at Goslar, in the Hartz. 

 It is there called Misy, a name given to it also by Professor 

 Hausman.* At all events, it will be advantageous to keep this 

 name for the substance, when once it will be better described, 

 and received as a species of its own in the mineralogical sys- 

 tems, and not to apply the name of Misy to the red salt above 

 described, as is done by Leonhard.-f- Misy is an old name 

 occurring in Pliny, j It is difficult to ascertain the exact ori- 

 ginal meaning of it, if it did not refer to the decomposed alum- 

 slate, impregnated with various kinds of salts. 



Art. V. — Account of the Great Cavern of Boobon in the 

 Cossyah Mountains. By M. Duvaucel. || 



It is well known that there is a subterranean cavern at the 

 foot of the Cossyah Mountains ; but very few Europeans have 

 seen it, because it is out of the Company's territories ; and I 

 am convinced your numerous readers will peruse a description 

 of it with interest. , 



This immense excavation, which seems to be made by the 

 passage of the rain waters across the rocks, is without doubt 

 the largest that is known. Neither the grottos in Germany, 

 nor the cavern of St Patrick in Ireland, nor that of Bauman 



• Handbuch, § 1058. f Ibid. § 113. t Lib. xxxiv. cap. 12. 



II Having referred to this paper in a brief notice of the Cave of Boobon in 

 this Journal, No. xv. p. 64, and having found that M. Duvaucel is a tra- 

 veller of veracity as well as a learned naturalist, we are persuaded that our 

 readers will be gratified with the following translation from the descrip- 

 tion of the cave originally published in French in the Calcutta Journal. — 

 Ed. 



