Although two distinct beds, only, of fossil salt have been met with at Northwich, it has been ascertained that the same limitations do not exist throughout the whole of the salt district. At Lawton, near the source of the river Wheelock, three distinct beds have been found, separated by strata of indurated clay: one at the depth of one hundred and twenty-six feet, four feet in thickness; a second, thirty feet lower, twelve feet in thickness; and a third, forty-five feet further down, which was sunk into seventy-two feet, without passing through its substance. The intervening clay, the structure of which is very peculiar, is called the shaggy metal, and the fresh water which passes through its pores has the expressive appellation of Roaring Meg. This epithet will not appear too strong, when it is mentioned that in a mine in which the section of strata was taken, and where the “shaggy metal” was found at the depth of about eighty feet, the quantity of water ascertained to issue from its pores in one minute, was not less than three hundred and sixty gallons; a circumstance which greatly enhances the difficulty of passing a shaft down to the body of rock-salt. In many of these beds of argillaceous stone, a portion of salt, sufficiently strong to affect the taste, is found to exist; and this saltness increases, as might be expected, in proportion as the body of rock-salt is approached. In the strata or layers immediately above the rock, which in all the mines are perfectly uniform in their appearance and structure, this is particularly remarkable, notwithstanding there are not, in these strata, any veins of rock-salt connected with the great mass below. On the contrary, the line between the clay and rock-salt is drawn with great distinctness in every instance, without presenting any of those inequalities which would arise from a mutual penetration of the strata. Not any marine exuviæ, or organic remains, are found in the strata above the rock-salt; and the almost universal occurrence of gypsum, in connection with beds of fossil salt, is a fact still more deserving of observation, because it appears, not only in these mines, but also in the salt mines of Hungary, Poland and Transylvania; on which account Werner, in his geognostic system, assigns to the rock-salt and fletz gypsum a conjunct situation.