Regarding the original formation of rock-salt, there are many opinions, theories and conjectures, and to the present day it is an undecided question. We are, as I have previously stated, in complete ignorance of the origin of the chloride of sodium; we must consider it as one of those geological secrets upon which we shall never be able to enlighten ourselves, if we cannot obtain stronger evidence than that which we have at present. Science is at fault in this, as she is in many other subjects which have perplexed and interested from time to time those who study and seek to unravel the various obscure and complicated phenomena of nature. No satisfactory or elucidatory theory has, as yet, been advanced to account for the occurrence of the formation of salt. Some geologists have maintained that it was deposited from the ocean, but in what way they do not explain; indeed, it is difficult to suppose how it could have been so, for salt, or rather sea water, holds in solution many ingredients which are not present in this rock. Besides, the several strata above it contain organic remains, as do also those below, though altogether of an entirely different kind; rock-salt itself contains none whatever; from this fact some have inferred that the formation took place during the epoch which elapsed between the destruction of one creation and the calling of another into existence. Others suppose that it is simply the result of volcanic action: this hypothesis is correct to a certain extent, as far as isolated salt lakes like that of Tsomoriri in Western Thibet, and that lake midway between Bombay and Nagpur, are concerned; or those huge mountains consisting entirely of fossil salt, like the one near Cardona, fifty miles from Barcelona, in Spain, or those in Lahore, or in Peru; but it altogether fails as regards non-isolated salt lakes and salt marshes, or such a large inland sea as the Caspian. Some light may be thrown upon it by the recent explorations in the North-Western Provinces of India, for Mr. Wynne tells us that “the geological structure” (of the Indian Salt Range) “of the trans-Indus extension of the Salt Range repeats in a great measure that of the western portion of the Salt Range proper, but with some considerable differences. The Palœozoic rocks, so far as presented by the red-marl, rock-salt, and gypsum, are quite the same, and so are the Carboniferous and Triassic groups, but others of the sub-Carboniferous beds present themselves with a different association from those of cis-Indus.” Mr. Wynne also informs us that the mineral productions of the range are valuable, and consist of the salt of Kalabagh and the Lun Nullah, the alum of Kalabagh and the Chichali Pass, the coal or lignite from the Jurassic[41] beds of the Kalabagh Hills: we also learn that gypsum is present with the salt, as it is in Poland, Transylvania, and Hungary; for in these three countries there is a layer of gypsum between the stratum of stone and the bed of salt.