the sandstone rock at Rosebury-2ndly, from that of the Clent Hills, and 3rdly, from the sandstone of Ombersley, Martley, &c. It is of consequence to understand the situation of the town of Droitwich, in relation to the Red Marl formation in its immediate vicinity. The borough of Droitwich is built in the very lowest part of a vale which runs nearly east and west for about a mile and a half, viz.—from Hanbury Wharf to some little distance beyond the western end of the borough. The valley then takes a southwesterly course, through Salwarp and near Westwood: the high grounds of the latter place rising on its western side, and the line of country through which the road passes from Worcester to Droitwich forming its eastern boundary. The valley from thence is continued to Hawford Bridge, and soon after it terminates at the bank of the Severn. Through this vale runs a small river called the Salwarp, which evidently takes its name from the Latin word Sal-Salt. This river, commencing at Bromsgrove Lickey, takes a southerly direction, passing by Stoke Prior and near Rashford, soon after which it enters the valley of Droitwich, about half a mile to the east of the town. The stream then runs westerly, and passes directly by the town, at the western extremity of which its course is altered, and it thence pursues nearly a south-westerly direction, through the bottom of the valley before described, until it empties itself, passing under Hawford Bridge, into the Severn near to Bevere. Advantage of this valley has also been taken by art to cut through it the Worcester and Droitwich canal, for the purpose of conveying salt to Worcester; the canal following nearly the course which nature has pursued in carrying the river into the Severn. The river has, throughout its course, a gravelly bed, and the pebbles are principally of quartz.

It may be worth while to point out that rivers or rivulets passing through a country, are often connected with vallies or concavities, which they seem once to have formed or occupied. This may be the case with the small rivulet which now runs through the valley of Droitwich. A great lake may formerly have filled the valley, and the gravel, sand, clay, and loam which are now found in every part of it, may have been mechanical deposits from water, the action of which may have rolled and rounded the pebbles. This circumstance it is of importance to keep in view, because it has a relation to the mode by which the salt is by some geologists supposed to have been produced.

Examples, on a large scale, of such concavities as the valley of Droitwich are frequently found. They are met with in the course of the Rhine, the Rhone, the Elbe, and the Danube. The Vallais, and the concavity in which the lake of Geneva is situated, shew this appearance in the line of the Rhone; the lake of Constance in that of the Rhine. They occur in Scotland in Dumfriesshire, Perthshire, and Aberdeenshire. The

Tay, at Perth, before issuing from the narrow pass between the hills of Kinnoul and Moncrief, affords an instance.

The necessary consequence resulting from the town of Droitwich being built in a valley is, that from whatever road you enter it, you must descend. The approach from the south is by the Worcester road, and when within a quarter of a mile of Droitwich, after having travelled for some miles on gravel, you arrive at an eminence of Red Marl, which is exposed to view. This eminence is about eighty feet higher than the bed of the canal, which runs through the town; and the high, marly ground is continued to the east and to the west, forming a line of low hills to the south of the town. Descending by a gentle slope, you arrive in the valley, where the houses are built on the Salwarp, the small stream before noticed, which springs from Bromsgrove Lickey, having all the way a gravelly bed. If when in Droitwich you look to the north, you see rising ground springing up rather precipitately. This is Dodderhill, which is close to Droitwich; the church is built upon marl, resembling that which has been noticed as occurring to the south of the town, and there is a good section of it exposed to view. Dodderhill is, however, still higher than the marly banks to the south. It is nearly 100 feet above the canal, and this high ground is continued easterly and westerly. Passing out of Droitwich on the east side by the Hanbury road, you do not so immediately ascend; but at the distance of less than a mile from the town, at Hanbury Wharf, the ground is seventy feet higher than the bed of the canal, and near this place, on the side of the road, there is a section of marl. To the west, towards Kidderminster, the ground rises in about the same ratio as towards the east, but not so abruptly as to the south and north; and here also, at the extremity of the town, are sections of red marl with green veins. Droitwich, then, may be considered as lying at least seventy feet lower than any of the ground in its immediate vicinity.

In every part of the county that I have been just describing, even near Dodderhill, there are gravel beds, varying very much in thickness; and the pebbles and stones contained in these beds are chiefly disintegrations from the older rocks, consisting of Quartz, Sienite, Granite, Trap, Old Red Sandstone, &c. I have not yet heard of any fossil bones of the Mammoth and Hippopotamus having been discovered in them.

Lias. At the part of the Red Marl formation we have been now considering, and where the salt is principally found, we approach a different geological formation. This is the Lias Limestone, which is higher in the series of rocks than the sandstone formation. It extends in this county from near Bentley and Hanbury, in a line nearly southwards, to the junction of Worcestershire with Gloucestershire, near Tewkesbury. It is of importance to bear in mind, that wherever salt has been found in this county, it has been at no great distance from the junction

of the Red Marl with the Lias; for example, at Droitwich, at Stoke Prior, and also near Croome and Upton. The Lias is the next in the ascending series of secondary strata to the Red Marl; and every point in this county, where the marl approaches the Lias, it is more argillaceous than it is about Bewdley and Kidderminster, and Martley and Ombersley; in all of which places the sandstone has much greater firmness, and assumes a rocky appearance. In this county the salt then is found in the softer or argillaceous marl, and not in the firmer or lower beds of sandstone.

The most northern point of the Lias formation in Worcestershire is near Lower Bentley. From this place its line of junction with the Red Marl passes about one mile south-east of Hanbury, and thence at the back of Meer Hall to Goose Hill, and on the north of the Trench woods to Crowle; its course being for the most part marked by a low range of hills. At Crowle there is a good section of it, shewing very distinctly its junction with the red marl. From Crowle, the line of junction crosses successively the roads to Alcester, Evesham, and Pershore, and it then turns due south, passing close to Pirton, and crossing Croome Park, where it forms a low bank, with the house at the foot and the gardens at the top. From Croome the Lias may be traced to Baughton Hill, which is about two miles and a half north-west of Upton. Thence it runs nearly south, crossing the Worcester road and forming a good junction with the Red Marl near to Ripple. Pursuing the investigation further, due east, over to the opposite bank of the Severn, several patches of Lias may be discovered, the most northern of which is an outlyer at Longdon Heath, a mile and a half south of Upton. The Lias thence runs south by Pull Court, and soon afterwards we pass into Gloucestershire, to which these observations are not intended to reach.

It will now be seen that nearly the whole of the southeastern extremity of Worcestershire belongs to the Lias formation; and I have drawn attention to this fact, in order that the source of the saline springs, which arise in this part, and whose properties so nearly resemble those of Cheltenham and Leamington, may be investigated.

The saline springs which occur in this part of Worcestershire

are

1st. The Hampton Spa, near Evesham.

2nd. The Hasler spring.

3rd. The Defford spring.

4th. A spring near Bourn Bank, Upton. 5th. A spring at Churchill, near Spetchley. 6th. A spring near Stone Bow Turnpike. 7th. A spring at Cauldwell;

and also springs at Abberton and Pinvin,-to which we might also add, as closely adjoining our county, the springs at Tewkes

bury and Walton. There is likewise a spring of this nature at Redmarley. Now most of these springs, in addition to the chloride of sodium, or common salt, which is found in the brine springs at Droitwich, contain certain other ingredients, which they appear to imbibe by passing through the strata of Lias. These ingredients are sulphate of soda and magnesia, to which may likewise be added, though they exist only in small quantities, sulphate of lime, and chloride of magnesium. In addition to these ingredients, the Hasler water is said to contain a small portion of sulphuretted hydrogen.*

Mr. Murchison, whose talents as a distinguished geologist are too well known to need any comment from me, endeavours to account for the existence of the mineral waters at Cheltenham, the whole of which immediate neighbourhood is Lias formation, by supposing that they are all primarily derived from a great subterranean storehouse of rock-salt situated very deep in the earth, and that at Cheltenham the springs so saturated with salt have superadded to them, by percolating through the Lias strata, the sulphates of soda and magnesia and the oxide of iron, which are found in those waters. He says, "These facts may be accounted for under the supposition that the source of the saline ingredients of those waters is the New Red Sandstone, the uppermost strata of which must, from their known inclination, lie at depths of several hundred feet below the town of Cheltenham. If this be the case, and that saline waters are continually flowing upon the inclined surface of these beds, we can readily explain why they occasionally rise to the surface; for waters collected in the New Red Sandstone, at higher levels than the vale of Gloucester, would naturally ascend to their original level by any cracks or open veins which might present themselves in the overlying Lias. The salt water having to pass through various strata of marl and clay, loaded with iron pyrites, or sulphuret of iron, it is to be presumed that during this passage, certain chemical changes take place, which give to the waters their most valuable medicinal qualities."

I have before observed, that although in this county rock-salt and gypsum are found in the Red Marl, this is not the only geological situation in which these minerals occur. There is an instance of a salt spring issuing from the coal measures in this county, near Dudley. Salt springs rise in many of the coal strata, and gypsum and rock-salt are found both in the upper, secondary, and tertiary beds.

I shall not attempt to describe the various situations in which rock-salt is discovered, because it would be impossible

*The water containing sulphuretted hydrogen was obtained whilst sinking a shaft for coal, at the depth of twelve feet from the surface. The shaft is now filled up, but close to it a well, twenty feet deep, has been sunk, and from this well saline water is still obtained; but in the specimens I have procured no sulphuretted hydrogen was discovered.

to do so within the limits of the present article; but I may just remark that in Cheshire, where it must be familiar to most persons, that rich mines of salt exist, this mineral is found, as in Worcestershire, associated with Red Marl. There the solid beds of salt are worked, and are of immense thickness. The upper bed in that county, which is about forty-two yards below the surface, is at least twenty-six yards thick, and is separated from a lower bed by a stratum of argillaceous stone, ten yards thick. The lower bed of salt has been sunk into forty yards. But these salt formations become insignificant, when compared with some of those on the continent. Count Laborde tells us, that at Cardona, in Spain, there is a salt mountain that has not been worked, which is six hundred and sixty-three feet in height, and twelve hundred and twenty-three feet in breadth at its base. "Nothing," says he, can compare with the magnificence of the spectacle which the mountain of Cardona exhibits at sunrise. Besides the beautiful forms that it presents, it appears to rise above the river like a mountain of precious gems, displaying the various colours produced by the refraction of the solar rays through a prism."

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The salt mines of Hungary and Poland are the most extensive repositories of rock-salt in Europe; and the details connected with them are so curious, that it would be desirable to give some description of them; but this passing notice may serve to call attention to the geological formation of rock-salt in those countries, which does not very greatly differ from its connexion with the Red Marl in this country. It is gratifying to us, as a commercial people, to be informed that a greater quantity of salt is exported from this kingdom than from all other nations; and that notwithstanding Poland contains the most extensive salt-mines, the advantages this country possesses in facility of transport enable us to supply a large portion of that country with salt. were not placed beyond doubt, by official returns, it would appear incredible that upwards of four hundred thousand tons of salt are exported from Liverpool annually, the whole of which is furnished by the mines of Cheshire.

If it

In regard to the original formation of the beds or strata of rock-salt, in this and other countries, different theories, opinions, and conjectures have been formed and proposed; but it is one of those geological questions, which are extremely embarrassing in their nature, and very difficult in their solution. It is worthy of remark that wherever rock-salt is met with, sulphate of lime or gypsum seems to be very generally discovered, in mixture with the earthy strata above it. In most parts of the world where these gypseous strata are found, marine shells are mixed with them; but this has not been discovered to be the case either in Cheshire or in this county.

Many persons have been induced to consider the beds of rocksalt in Cheshire and in this county as so many deposits of salt