96 
Records of the Geological Survey of India. 
[vol. III. 
of the schists may have taken place and continued until they became tilled with ore and so 
given rise to the appearances which have been regarded as indicating the existence of lodes. 
If this view be correct then the highly metamorphosed rocks which occur in the otherwise 
uninterrupted strike of schists at Akarsuni and Kumerara must be derived from the schists 
by excessive local metamorphism. But if, on the other hand, these rocks belong to the 
older metiimorphies which they certainly at first sight appear to do, then the lode hypothesis 
must be admitted to be true. 
Reviewing the evidence on both sides, the legitimate conclusion to be drawn would seem 
to be that the copper of Singhbkum in all probability occurs both in lodes and as a 
deposit disseminated throughout the materials which compose the schists. Similar cases 
of double conditions of occurrence are not unknown in other countries, as will be alluded 
to again further on. 
Okes. 
The ores of the upper part, or, as it is technically called the ‘ back’ of the deposit, have 
all been converted into carbonates and oxides. 
In assays made upon eight different qualities of ore by M. R. Schenck, and quoted 
in the Hindostan Copper Company’s prospectus, the contained copper varies between 35 03 per 
cent, and 1'46 per cent. Three analyses by Messrs. Phillips and Darlington of specimens 
of carbonates gave the following results :— 
No. 1.—Copper 31*5 per cent. Silver 2oz. Sdwts. 17grs. per ton of ore. 
No. 2— „ 6*26 „ „ 1 M 2 „ 20 „ 
No. 3.— „ 6’0 „ „ 0 „ 19 „ 14 „ „ „ 
Three other specimens were examined hy Messrs. Howard and Dollmau and gave the 
following results:— 
No. 1.—18*8 per cent, of copper. 
No. 2.—21'8 ,, „ 
No. 3—24*0 „ „ 
Three specimens brought by me from Jamjura yielded according to Mr. Tween’s 
analysis— 
No. 1.—Jamjura ore, copper = 52*o per cent. 
No. 2.— „ „ = 44*5 „ 
No. 3.—Dugni „ = 36*5 „ 
Nos. 1 and 2 were picked specimens, but No. 3 was the ordinary ore to be found 
at Dugni. 
Messrs. Henry Bath & Sons, to whom some of the ores, smelted to a regulus, were sent 
in 1854, reported as follows :—“ Our assayer has carefully tested the samples thou sent us ; 
they contain about 50 per cent, of iron which makes them very difficult to smelt, and 
is also very prejudicial to their sale ; we thiuk, however, that the prices affixed to them may 
be obtained.” 
We are thy sincere friends, 
IIenky Bath & Sons.* 
Mining Office, Swansea, 8mo., 19, 1854. 
No. 1.—Copper, 42 per cent. £37 per 21 cwt. 
No. 2— „ 
41 » 
35-15 
No. 3.— „ 
39 „ 
34-2 
No, 4.— „ 
36 „ 
31 
The assays above quoted were of the carbonates or of grey-copper. 
Copper pyrites occurs in the schists at Rajdoha; it was first found there by the second 
company; fragments of rock permeated with it are still to be found in tbe debris. It seems 
to have been little affected by the weather. 
* Proceedings Asiatic Society of Bengal, XXIV, 1855, p. 706. 
Notb. —Of the minerals occurring in the schists, the following arc the principal which have been met with : 
Garnet, Schorl, Kvanitu, Chlorite, Tremolite, and Aetiuolite. In the hill Dari, which is formed of potstone under¬ 
lying the schists, a peculiar indurated talc occurs in veins. The potstones arc extensively quarried, and 
supply a plate factory in the neighbouring village. At Jamjura M. Stcehr discovered an interesting carbonaceous 
mineral, of which I also obtained specimens in the refuse heaps when 1 visited that locality; it is described 
in the Mining and Metallurgical Journal for 3rd June 1859. 
