ON THE SALT SPRINGS OF WORCESTERSHIRE 33-7 from sea water. Granting this view to be correct, it would greatly favour the supposition that the valley of Droitwich was at one time part of a salt-water lake. Those who maintain this to be the origin of salt say, that whenever the sea water in the valleys became separated from the sea, the salt contained in it would subside by the natural process of evaporation, which would be much assisted by any internal heat of the earth below the water. One strong objection to this view is the fact, that the rock-salt of Cheshire and Droitwich differs much from that contained in the sea, inasmuch as the earthy salts of magnesia, which are found mixed in the waters of the ocean, do not exist in the brine of Cheshire or of Worcestershire. There is also a very strong proof against the notion that the beds of rock-salt in these two counties are depositions from sea water, in the circumstance that no marine exuviæ have ever been found in the strata. Other objections also offer themselves to the validity of this theory; such as the enormous depth of sea water necessary to the production of a body of rock-salt forty yards in thickness, and also the difficulty of accounting by this means for the mountain of rock-salt at Cardona, in Spain, to which I have before alluded. Nevertheless, the high authority of Mr. Lyell seems rather to favour the opinion that there may have occurred immense depositions of salt in the above manner. He says in his Principles of Geology, when speaking of the Mediterranean-"What profundity, then, may we not expect some of the abysses of this sea to reach! The evaporation being, as we before stated, very rapid, the surface water becomes impregnated with a slight excess of salt; and its specific gravity being thus increased, it instantly falls to the bottom, while lighter water rises to the top, or that introduced by rivers and by the current from the Atlantic flows over it. But the heavier fluid does not merely fall to the bottom, but flows on till it reaches the lowest part of one of those submarine basins, into which we must suppose the bottom of this inland sea to be divided. By the continuance of this process additional supplies of brine are carried to deep repositories, until the lower strata of water are fully saturated, and precipitation takes place; not in thin films, such as are said to cover the alluvial marshes along the western shores of the Euxine, nor in minute layers, like those of the salt'étangs' of the Rhone, but on the grandest scalecontinuous masses of pure rock-salt extending, perhaps, for hundreds of miles in length, like those in the mountains of Poland, Hungary, Transylvania, and Spain."* There can be no doubt that the whole of the vale of Worcestershire has been at some distant period part of the bed of an immense ocean, and therefore it is possible that our salt may have been deposited in some such manner as Mr. Lyell thinks is * Vol. 1st, p. 298. July, 1835.-VOL. II. NO. XII. 3 B now taking place in the bed of the Mediterranean sea. But it is certain that chloride of sodium, or salt, is one of the products of volcanic emanations, and of springs in volcanic regions, and that these springs are also found in the tertiary, transition, and primary rocks; and therefore the original source of salt may be as deeply seated as that of lava. Salt springs also rise through granite, which again connects them with igneous phenomena. The hot spring, for example, at St. Nectaire, in Auvergne, may be mentioned as one of many containing a large proportion of chloride of sodium, together with magnesia and other ingredients.* It seems, therefore, most congenial to the spirit of true philosophy, in the imperfect state of our knowledge of those circumstances which have governed the deposition of salt in the strata of the earth, not to lend an implicit belief to any theory that may be propounded. We shall, at present, best insure the progressive advancement of geological science by industriously accumulating facts, and cautiously drawing conclusions from them, rather than by prematurely arriving at conclusions, which may turn out to be erroneous, and stop that ardour of investigation which never fails to urge on the powers of the mind to exertion when important facts are still to be discovered. In truth, every student of geology should have his mind strongly impressed with the danger that he falls into by hypothetical reasoning, and all those who may be so disposed should keep in mind the example of Saussure, of whom it is related as a geologist, that in proportion to the avidity with which he sought for facts, was the care with which he avoided vain speculations. If he sometimes advanced an hypothesis, it was with a reserve justly admired, although rarely imitated, and only when the facts seemed imperiously to command it. When new facts came in opposition to his former opinions, he abandoned them, or modified them without regret. It is by this sober attention to facts, and by orderly arrangements, that modern geologists have been able so much to advance their science. An excessive fondness for theorizing, unconnected with accurate observation, was the sin of the scientific writers of the sixteenth and seventeenth centuries; and geology, in common with several others of the physical and experimental sciences, has had more difficulty in removing the rubbish which her ill-judged admirers had placed in her way, than in overcoming the natural obstructions of her path. Limestone, for example, was considered as entirely the result of animal action, and the various formations of that rock were viewed as accumulations of altered shells and corals. But neither shells nor corals occur in primitive mountains, although these often contain extensive beds of limestone, and although lime has been proved to enter into the composition of most of the simple minerals of which primitive rocks are composed. It is therefore evident that lime is an * Annales de 'lAuvergne, tome 1, p. 234. original substance in primitive mountains, and has been formed at times independently of animals. Salt also may be, and probably is, an original production in the bowels of the earth. It is not, however, my intention to pursue further these speculations, but rather to confine our attention to certain particulars connected with the salt springs in Worcestershire. Droitwich and Stoke Prior are the only situations in which salt is now worked for manufacture; but there can be little doubt that other springs exist in this county. I have before mentioned that the neighbourhoods of Upton and Croome afford indications of salt; I may also notice the farm called the Brine Pits, in a north-easterly direction, two miles and a half from Wich; and, according to Camden, it appears that prior to his time several weaker pits of brine had been worked in various parts of Worcestershire, but they had been closed to prevent the excessive consumption of wood, which, before the discovery of coal, was the article used for evaporating the water from the salt. I may also observe that there is reason to think that in the immediate neighbourhood of Worcester brine may be found. At the distillery on the west bank of the Severn, Mr. Williams sunk a well of great depth, from which he procured salt water. In cutting through the strata for this well, when at the depth of about 110 feet, they came to marl, with which was intermixed abundance of gypsum, and the water that was procured rather lower was impregnated with saline matter. It does not appear certain at what period the manufacture of salt was first carried on in this county, but we know that at Droitwich pits have been worked from very remote times. Salt was an object of taxation at a very early period. Ancus Martius, 640 years before our era, "Salinarum vectigal instituit." This tribute was imposed on the Britons, when our isle was possessed by the Romans, who worked the Droitwich mines, and who made salt a part of the pay of their soldiers, salarium or salary; hence the custom at the Eton Montem of asking for salt. At this early time in the manufacture of salt, prior to the use of coal, the evaporation of the brine was effected by the burning of wood, and serious inconvenience began to be felt in consequence of the forest of Feckenham being gradually diminished by the demands for the salt pits. Leland says, "For making salt is a great and notable destruction of wood, and hath been and shall be hereafter, except men use much coppices of yonge wood." "The lacke of wood is now felt in places near the wyche. For whereas in places near about they used to buy and take their wood, the wonted places are now sore decayed in wood. They be forced to seek wood as far as Worcester, and all the parts about Bromsgrove, Aulchurch, and Aulcester." "I asked a salter how much wood he supposed yearly to be spent at the furnaces, and he answered that by estimation there was spent six thousand loads yearly." This observation forces upon us the consideration of the importance of coal to the manufacturing prosperity of this great country. It is manifest that, but for the circumstance of coal having been made subservient to evaporating the brine, long ere this the manufacture of salt must have ceased in this county. Instead of that occurrence taking place, subsequent events have shewn that commercial enterprizes and welldirected speculations have greatly increased the produce of salt. Until the year 1725 the brine that was procured to evaporate was comparatively weak, and afforded but a small proportion of salt. In fact it was yielded by superficial springs, situated above the bed of gypsum or talc, and the working of the pits afforded but little advantage to the proprietors. In that year, Sir Richard Lane, Mayor of Worcester, made a most important discovery, which added great value to the salt springs, and in consequence of which the quantity of salt procured from these springs has been ever since very much increased. He, being informed by some persons concerned in the salt works of Cheshire, that the strongest brine in that county lay lower than the pits in Droitwich were commonly sunk, ordered the gypsum which was at the bottom of the pits to be sunk through. Upon this the strong brine broke through in rich abundance into the pits. This was indeed a grand revolution in the brine pit speculations, and one which has been productive of most important effects to posterity; but, however, like most other revolutions, it was the occasion of considerable evil to many persons who were then concerned in the manufacture of salt, to whom the old or superficial pits belonged. Dr. Nash says, "From henceforth the old pits became of no value at all, which some years before were worth near £5000 per annum, and esteemed the surest property a man could enjoy. Charities designed to be perpetual were funded in it; many women were jointured upon it; and such an estate was in every respect judged far preferable to land. So that the confusion and distress which ensued in the town and neighbourhood cannot easily be described." So it is in the great scheme of communities that changes are continually occurring, ruinous to individuals, but which work together so as greatly to increase the prosperity of the State. We cannot here also help pausing to remark, how singular it appears, that nearly two thousand years prior to the discovery of the strong brine, man should have been directed, probably by the circumstance of the saline springs coming to the surface, to evaporate the weaker brine, and should have gone on for that long period making use of this weak solution to procure the salt, when, if he had only dug a few feet deeper, much richer brine would have been found, which would have more amply repaid him for the trouble of working it. The obvious conclusion from this observation is, that we know not what treasures may yet be in store for us buried in the earth's bosom ; and it enforces upon us the conviction, that in studying the stratification of the crust of the earth, we are not only doing what ON THE SALT SPRINGS OF WORCESTERSHIRE. 34t must inevitably add to our present happiness and enjoyment, but also that our researches may lead to great practical advantages. With respect to the depth below the surface at which the brine is procured, I may, in the first place, observe, that the marl from twelve to eighteen feet from the surface, which is about the depth of the pump wells at Droitwich, is abundantly supplied with springs of water, which, in many parts of the town, afford very good pump water for domestic purposes. But this is not the case in parts of the town near to the south bank of the river Salwarp. Many of the wells in this direction, which are not much above twelve feet deep, yield water so much impregnated with salt as to be unfit for domestic purposes. I evaporated some water, for example, obtained from a pump in the town a little to the south of the canal, and procured from a pint of water 540 grains of salt.* I dwell upon these circumstances in order to shew that it was probably the salt-springs rising so superficially which in the first instance directed the inhabitants in by-gone times to become salt-makers; for it appears that this superficial indication of salt is a very good guide to it at a greater depth, most of the brine pits that are now worked occurring in the part of the town where these superficial weak brine springs prevent the inhabitants from having good pump water. These springs, however, would be of little use in affording brine for evaporation, the quantity of salt contained in them being much too small to repay the expenditure occasioned by the consumption of the coal necessary for that purpose. In order to obtain the brine fit for evaporation, so as to afford a remuneration for the expence of this process, it is necessary to penetrate very much deeper. The section from the surface is as follows:-First a stratum of mould, three feet deep; then a stratum of red marl, forty feet deep, which abounds with water of a brackish nature. After that a stratum of marl, which extends for 130 feet. In this marl there are no springs of water: it is quite dry, but is penetrated with perpendicular veins of gypsum (sulphate of lime). At the *No. 1. South of canal. Solid contents 540 grains in 16 fluid ounces. Soda and lime, combined with muriatic and sulphuric acids, with a trace of iron. No. 2. Norbury's. Solid contents 12 grains in 16 fluid ounces. Lime and soda, combined with muriatic and sulphuric acids, with a slight trace of iron. No. 3. Penrice's. Solid contents 8 grains in 16 fluid ounces. bined with muriatic and sulphuric acids, with a slight trace of iron. No magnesia indicated in either of the above-no iodine. Lime, com The average depths of fresh water springs in the vicinity of Droitwich are as follows, viz. : |