1856.] Proceedings of the Asiatic Society. 579 



Fob December, 1856. 



At a Monthly General Meeting of the Society held on the 3rd 

 instant, at the usual hour. 



The Venerable Archdeacon John H. Pratt, senior member present, 

 in the Chair. 



The proceedings of the last meeting were read and confirmed. 



Presentations received — 



1st. — From the Government of India, at the request of Captain 

 Yule, a copy of his narrative of the mission to the Court of Ava. 



The thanks of the meeting were voted to Captain Yule for his 

 good offices in obtaining for the Society, this interesting and valu- 

 able addition to its Library. 



2d. From Capt. W. S. Sherwill, F. G-. S., a series of specimens 

 from the Borrowdale Plumbago Mine in Cumberland, collected by 

 him on the spot, consisting of — 



1. Slaty rock (upper Silurian) from Borrowdale, 500 feet below 

 the Greenstone Porphyry, containing the Plumbago carburet of iron. 



2. Greenstone containing iron pyrites (sulphuret of iron) found 

 in close proximity to the plumbago. 



3. Greenstone porphyry discoloured with oxide of iron, the red 

 oxide is considered by the miners as a sure index and guide to the 

 presence of plumbago. 



4. The red oxide is here shown in conjunction with the plumbago, 

 the plumbago having been forced into narrow crevices in the green- 

 stone rock, the mineral bearing marks or striae caused by friction. 



5. The plumbago in small nests embedded in greenstone por- 

 phyry. 



6. Greenstone porphyry strongly impregnated with plumbago. 



7. Tolerably pure plumbago. The striae where it lay against 

 the containing- rock are still visible upon its surface. 



8. Specimens dug from a nest of plumbago that was found em- 

 bedded in greenstone porphyry (No. 6.) This quality is used in the 

 manufacture of lead pencils. 



9. Plumbago of divers degrees of purity and value, also used for 

 pencils. 



10. The purest specimens of plumbago obtainable, valued £30 

 a ton. 



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