178 Miscellaneous Intelligence. 



III. Natural History. 



1. Extraordinary formation of Hornstone. — Professor Jameson 

 in some speculations in regard to the formation of opal, woodstone, 

 and diamond, gives the following statement: — " Like opal, horn- 

 stone seems sometimes to be a product of vegetable origin, for the 

 specimen which I now exhibit to the Society is a variety of wood- 

 stone. This remarkable specimen, which is eighteen inches long, 

 five inches thick, and eight broad, was torn from the interior of a 

 log of teak wood, (tectona grandis,) in one of the dock-yards at 

 Calcutta. The carpenters on sawing the log of teak wood, were ar- 

 rested in their progress by a hard body, which they found to be in- 

 terlaced with the fibres of the wood ; and, on cutting round, ex- 

 tracted the specimen now on the table. This fact naturally led me 

 to conjecture, that the mass of woodstone had been secreted by the 

 tree, and that, in this particular case, a greater quantity of silica 

 than usual had been deposited ; in short, that this portion of the 

 trunk of the tree had become silicified, thus offering to our observa- 

 tion in vegetables, a case analagous to the ossifications that take place 

 in the animal system. I was further led to suppose that the wood 

 might contain silica in considerable quantity as one of its constituent 

 parts, a conjecture which was confirmed by some experiments made 

 by Dr. Wollaston. Other woods appear also to contain silica, and 

 these, in all probability, will occasionally have portions of their 

 structure highly impregnated with silica, forming masses which 

 will present the principal characters of petrified wood. Indeed, I 

 think it probable that some of the petrified woods in cabinets are 

 portions of trees that have been silicified by the living powers of the 

 vegetable and not trunks, or branches, which have been petrified 

 or silicified by a mere mineral process." — Edin. Jour. ix. lfj5. 



2. Matrix of the Brazilian Diamond. — In Mr. Hewland's splendid 

 collection there is a Brazilian diamond, imbedded in brown iron ore ; 

 another also in brown iron ore, in the possession of M. Schuch, li- 

 brarian to the Crown Princess of Portugal ; and Eschwege has in 

 his own cabinet a mass of brown iron ore, in which there is a dia- 

 mond in a drusy cavity, of a green mineral, conjectured to be arse- 

 niate of iron. From these facts he infers that the matrix, or origi- 

 nal repository of the diamond of Brazil, is brown iron ore, which 

 occurs in beds of slaty quartzoze micaceous iron ore, or in beds 

 composed of iron glance and magnetic iron ore named by him 

 Itabirite, both of which are subordinate to what he considers as pri- 

 mitive clay- slate. — Edin. Jour. ix. 202. 



3. Native Carbonate of Soda in India. — Captain John Stewart 

 being, in the course of military operations, encamped on the banks 

 of the Chumbul, near the village of Peeplouda, just where the 



