[voL. xiir. 
2(j6 Records of the Geological Siiireg of India. 
salt water become purged by tbe forced circulation of fresb-water underground' 
from artesian pressure, so our fact is of small account in the argument for or 
against marine strata in the alluvium. It is, however, of great weight in the 
argument for the local and actually operative production of these deposits of salt;; 
for it is almost beyond question that, as a common phenomenon in Upper India, 
the saline condition of the upper water stratum is due to the present operation 
of assignable conditions upon the surface and subsoil waters, whether rain water 
or as derived by percolation or irrigation from rivers and canals. 
With such good evidence of a vera causa of salt production actually in opera¬ 
tion, it should certainly be an object of continued observation and study whe¬ 
ther such extreme cases of local concentration may not be brought within its 
action. It may, nevertheless, bo well to point out what alternatives remain for 
those extreme cases. We can, I think, confidently assert that the Arvali forma, 
tion (or rock series) is not the repository of rock-salt. These strata occur in 
many outliers far into the alluvium on the prolongation of the range, and always 
in the same condition of extreme disturbance. There is a strong probability 
that what is seen of them in natural outcrops throughout the range may bo 
taken as fully representative of the whole series. Of the Vindhyans it may be 
asserted with even groater certitude that, so far as seen, they do not and never 
did contain rock-salt. It has even been conjectured that this formation, so far as 
known, is of fresh-water or subaerial origin ; but this very conjecture might en¬ 
courage the supposition of contemporary salt deposition in contiguous areas 
while the undisturbed condition of those rocks would bo in favour of the total 
concealment of any such deposits at a lower level than the actual outcrops. The 
area of covered ground here is quite extensive enough to conceal any such depo¬ 
sits of Vindhyan or of any subsequent age; and thus there remains the possibility 
of such a source for the salt of Sambhar and of other localities of apparently 
unlimited production. 
Record op gas and mud eruptions on the Aeakan Coast on 12th March 1879 
AND IN June 1843. 
The following reports by the local officers upon cases of eruptive action on 
the Arakan Coast are in continuation of those published in the Records for 
February 1879, Vol. XII, ji. 70 :— 
From Libut.-Colonei AV. W. Pemberton, Deputy Commissioner, Kyouk-Phyoo, to the 
Commissiouer of Arakau, Akyab,—No. 4i-14, dated 23rd June 1870. 
Referring to your endorsement No. 451-222, General, dated 7th May last, on the 
subject of a recent volcanic eruption, I have the honour to state as follows :— 
The Extra Assistant Commissioner of Cheduba was asked for a report on the subject, 
and ill his reply he states that the eruption did not occur on the i.sland of Cheduba. Some 
fishermen, who were out at .sea-fishiiig at the time of the occurrence, told him that they had 
