GRAPHITE IRON. 05 



amorphous to the graphitic condition is, as far as my observations go, 

 never complete, and is generally very partial indeed. The following 

 assays'* of semi-graphitic Damiida schist from the Rakti naddi, and of 

 so-called graphite collected by Captain Sherwill, and now in the 

 Geological Survey museum, show how small the percentage of carbon is : — 



Ash. 

 Rakti naddi ... ... ... ... 92-0 



Near Pankabari (Sherwill) ... ... ... 83'8 



Near Karsiang (Sherwill) ... ... ... 84*6 



The ash consists mainly of quartz and other silicious matter. It 

 is scarcely necessary to say, that even if all the carbon were true 

 graphite, a mineral containing 85 per cent, of ash is commercially worth- 

 less. It is no doubt possible that purer layers may exist ; fair specimens 

 of graphite have been obtained in the North* Western Himalayas-)^' 

 from strata similar to the Baling beds, and possibly including Damuda 

 rocks. I have never seen such, however, from the Darjiling hills, and it 

 is not probable that any really valuable masses of the mineral will be 

 found. Specimens of the Kumaon graphite even, which have been 

 sent to England for the opinion of manufacturers, have been pronounced 

 by them as useless, or, at best, as not worth more than £5 a ton. J 



Chapter VII. — Iron*— Copper — Lead. 



Iron. 



There is a strong ferruginous band included in the Tertiary sand- 

 stones of Lohargarh.S The out-crop runs along the 



Lohargarh. 



southern brow of the hill, with a thickness near 



the centre of perhaps 40 yards. The length of the out-crop being about 



a mile from east to west, or between the points where the band disap- 



* Made by Mr. Hughes. 

 f Vol. Ill, pt. 2, p. 180. 

 t Jour., As. Soc., Bengal, Vol. XXIV, p. 203. 



§ Dr. Hooker erroneously states (Himalayan Journals, Vol. I, p. 402), that the iron ore 

 is wholly superficial. 



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