lxxvi Proceedings of the Asiatic Society. [Sept. 1846. 



I have not sacrificed this very valuable little fragment to testing, 

 which would only shew us probably that it is a highly ferruginous sand- 

 stone, and have only satisfied myself that it is not magnetic ; for it is of 

 much higher interest than in a mere lithological point of view, inasmuch 

 as, when examined by the magnifier or even by the naked eye, it shews 

 exactly the structure of the Volcanic Bombs as described by Darwin 

 and other writers, being highly compact at the external surface, where 

 the iron also is in the state of a deutoxide, and of a loose concretionary 

 texture at the centre, where (and also at the surface from the effects of 

 exposure to the atmosphere), it is in the state of peroxide. 



When we look at the specimen in the sandstone it is difficult not to 

 suppose that it must have been imbedded there when the sandstone 

 was soft ! and we thus arrive at the conclusion that our little ferrugi- 

 nous bullets may have been volcanic grape shot, since their size does not 

 entitle them to be called bombs. I have written to Dr. Spilsbury for 

 more of these very curious specimens, when we shall be able to say 

 more of them. 



I have to announce also a further addition to our collection of Aero- 

 lites, being a second specimen obtained from the refuse of the Coal and 

 Iron Committee's Collections, probably from Assam. 



I at first thought that this was only another fragment of the former 

 one announced in my report of June last, and indeed it very greatly 

 resembles it in physical qualities, but upon chemical examination it has 

 proved to be an entirely different specimen, and a remarkable one, as 

 containing a considerable per-centage of Cobalt, of which the first is 

 entirely destitute, and very little if any Nickel, of which it will be re- 

 membered the first has a notable proportion. 



Museum of Economic Geology. — Dr. Spilsbury has also forwarded to 

 us a specimen of Copper-ore from the Sahgurh territory, about 60 miles 

 north of Saugor in Bundlecund, sent in by the Chief to the Deputy 

 Commissioner, Captain Hamilton,and said to have been worked in former 

 times, but it is so very poor an ore that it should rather be called a 

 Gossan.* I was in hopes that the greenish black crust at the surface 

 might contain Uranium, but it does not, being merely iron with a very 

 little copper. 



* The Cornish Miner's name for a ferruginous concretion more or less impreg- 

 nated with copper, which indicates at the surface the existence of veins below. 



