706 Proceedings of tlie Asiatic Society. [No. 7. 



Mr. Taylor has already large demands for this stone, but has very 

 handsomely offered to supply the Society at a very reasonable rate with 

 slabs for paving the lower floor. I have no hesitation in saying that such 

 a pavement, though less shewy, would be, for all practical purposes there, 

 almost equal to marble, which costs one rupee four annas per square foot. 



Copper ores exported in slags. — I have on more than one occasion, 

 when consulted as to the working of copper ores in this country, strongly 

 advised beginners not to attempt at first the refining process by which 

 marketable copper is produced, which is always best performed on a large 

 scale, and by men of long experience in such work ; but to fuse their ore, 

 after roasting it, into slags, and to export these to the smelters in England 

 where their market value would be properly known, and that they could 

 thereupon safely calculate their returns. 



Mr. Theobald, Senr. acting upon this advice in some experiments which 

 Mr. Mackenzie was undertaking with him in the Singboom territory, 

 smelted his ores to the slags upon the table, which I forwarded to a friend 

 in Swansea, who placed them in the hands of Messrs. Bath and Sons, pro- 

 fessional assayers there, whose report, as that on the first parcel of Indian 

 copper so sent to Europe, is well worth placing on record. 



" Our assay er has carefully tested the samples thou sent us, they con- 

 tain about 50 per cent, of iron which makes them very difficult to smelt, 

 and is also very prejudicial to their sale ; we think however, that the prices 

 affixed to them may be obtained. 



We are thy sincere friends, 

 (Signed) Henry Bath and Sons. 



Mining Office, Swansea, Smo. \9th, 1854. 



No. 1, copper 42| per cent. £37.0.0 per 21 cwt. 



No. 2, „ 41 „ 35.15.0 



No. 3, „ 39 „ 34. 2.0 



No. 4, „ 36 „ 31. 0.0 



Dr. Campbell on Darjeling copper. — The following copy of a letter from 

 Dr. Campbell, Superintendent of Darjiling, to Government gives an account 

 of that gentleman's very persevering efforts to test the value of his 

 copper ores. 



No. 229 of 1855. 

 To H. Piddington, Esquire, 

 Curator, Museum Economic Geology, Asiatic Society, Calcutta. 

 Sir, — I have the pleasure to send you copy of my last letter to Govern- 

 ment on the progress of my copper diggings. I shall keep the Society 

 regularly informed of any improvement in the quality of the ores. 

 I have the honor to be, Sir, 



Your most obedient servant, 



A. Campbell, Superintendent. 



