In the county of Sorry there arc great quantities of ful lers earth found about Nutfield, Riegatc, and Illechingley, to the south of the Downs, and some, but of inferior qua lity, near Sutton and Croydon, to the north of them. The most considerable pits are near Nuffield, between which place and Ricgate, particularly on Hadl!, about a mile to the east of Riegate, it lies so near the surface, as frequent ly to be turned up by the wheels of the waggons. The fullers earth to the north of the road between Redhill and Nutfield, and about a quarter of a mile from the latter place, is very thin; the scam in general is thickest on the swell of the hill to the south of the road. It is not known how long this earth has been dug in Sorry ; the oldest pit now wrought is said to have lasted between fifty and sixty years, but it is fast wearing out. The seam of fullers earth dips in different directions. In one, if not in more cases, it inclines to the west with a considerable angle. There are two kinds of it, the blue and the yellow : the former, on the eastern side of the pit, is frequently within a yard of the surface, being covered merely with the soil,—a tough, wet, clayey loam. A few yards to the west, the blue kind appears, with an irony sand stone, of nearly two yards in thickness, between it and the soil. The blue earth in this pit is nearly 16 feet deep. In some places the yel low kind is found lying upon the blue ; there seems, in deed, to be no regularity either in the position or inclina tion of the strata where the fullers earth is found, nor any mark by which its presence could be detected. It seems rather thrown in patches, than laid in any continued or re gular vein. In the midst of the fullers earth are often found large pieces of stone of a yellow colour, translu cent, and remarkably heavy, which have been found to be sulphate of barytes, encrusted with quiirtzose crystals. These are carefully removed from the fullers earth, as the say they often spoil many tans of it which lie about them. There is also found with the yellow fullers earth a dark brown crust, which the workmen consider as injurious also. In Surry, the price of fullers earth seems to have very little, at least for these last 80 years. In 1730, the price at the pit was Gd. a sack, and Gs. per load or ton. In 1744, it was nearly the same. It is car ried in waggons, each drawing from three to four tons, to the beginning of the iron rail-way near Westham, along which it is taken to the banks of the Ti.ames, where it is sold at the different wharfs for about 25s. or 26s. per ton. It is thence shipped off either to the north or west of Eng land. A considerable quantity is also taken clown into Wiltshire by the waggoners,, especially when they happen not to have a full load of goods.
The workmen are paid at the rate of 2s. 6d. per ton ; this includes the expellee of clearing away the upper soil, as well as that of raising the fullers earth. They can work on the earth only when the weather is dry ; it is then weigh ed as it is dug out, by means of a rude scale suspended over that part of the pit where they happen to be working, on three or four poles fastened tigethcr at the top, and spread out at their lower ends, (an instrument called pro vincially a triangle). The earth that is not immediately carted off by the waggons, is put under cover in an adjoin ing shed, in order to preserve it from the rain. During rainy weather, and after it till the earth is pretty well dried, the workmen employ themselves in uncovering the upper soil. The sandstone that lies over the blue fullers earth is broken into pieces ; the larger pieces are used for building, and the smaller for the roads ; the first brings 4s. 6d. the waggon load, the second 3s. 3d. ; of each of which the work men receive about one half. In the heart of the sandstone, pieces of petrified wood, of considerable size, and some times of a very grotesque shape, are often found. The workmen complain, that since the iron rail-way was brought to Westham, the demand for this earth, though equally great, is not nearly so regular as it used to be. It is thought that the demand for the Sony fullers earth will be lessened by the recent discovery of a pit of the yellow, or better sort, near illaidstonc in Kent. Fullers earth does
not appear to hasten or impede, to injure or to benefit, ve getation. See Stevenson's Sorry, p. 50-53.
The next characteristic stratum, owing to its forming a ridge of conspicuous bills through the country, is the Wo burn land, a thick ferruginous stratum, which below its mid dle contains a stratum of fullers earth, which is thicker and more pure in and llogstye End, two miles north west of Woburn, than in any known place. The upper parts of this land are frequently cemented by the oxidated iron into car stone, and the lower parts contain fragments of silicified wood. See Farey's Derbyshire, p. 112.
No stratum of this mineral occurs in Derbyshire ; but lumps of it of considerable size, very pure, and much like that of Bedfordshire, are frequently found in the marshy gravel pit one-third of a mile east of Bretby church. sr milar lumps occur in the hard gravel rock under Masham town, and smaller ones in the alluvial covering of the gyp sum quarries south-east of Chellaston. In Brassington a clay is dug, with which cloths are scoured ; and at Brath well, north-west of Tickhill in Yorkshire, considerable quantities of fullers earth are got, probably alluvia on the yellow lime. See Fancy's Derbyshire, p. 465.
Of the more rare kinds of earths and clays, there have been found red and yellow ochres, fullers earth, and tobacco pipeclay; but probably from the want or an adequate sup ply, or some imperfection in their qualities, they are now generally procured from other places. Fullers earth is, however, still dug occasionally for sale, in small quantities, on the estates of the late honourable Edward Foley, of Stoke Edith. See Dunscomb's Herefordshire.
Fullers earth is found at Tillington, and consumed in the neighbouring fulling mills. See Young's Sussex.
Mr Little and Mr Brown, in sinking a well at Padding ton in the year 1802, near the one mile stone on the Edge ware road, discovered a stratum of fullers earth at a con siderable depth, but so thin as not to be of any importance.. See Aliddleton's Middlesex.
The above seems to be nearly all the places in England where this mineral is best found. We have now to give :an account of its preparation by manufacturers, for their peculiar purposes. 1Ve have seen in the chemical account of this mineral, that it is not perfectly diffusible in water; but when immersed in that fluid, it falls into pieces of greater or less magnitude, or in such a manner as to assume the appearance of curds. Of this the manufacturers are fully aware ; but as it is necessary for them that the coarse and fine should be minutely separated, they pursue the fol lowing method. That they may effect a complete solu tion, they bake it for one or two hours, according to the de gree of heat. To accomplish greater regularity in the baking, and to make it dissolve much sooner, the large lumps are broken into pieces of a quarter or a half pound each. After baking it is thrown into cold water, when it falls into powder, and the separation of the coarse from the fine effectually accomplished, by a simple method used in the dry colour manufactories, called washing over. It is clone in the following manner: Three or four tubs are con nected on a line by spouts from their tops ; in the first the earth is beat and stirred, and the water, which is continu ally running from the first to the last through intermediate ones, carries with it andteposits the fine, whilst the coarse settles in the first. The advantages to be derived from this operation are, that the two kinds will be much fitter for their respective purposes of cleansing coarse or fine cloth ; and without baking the earth would be unfit, as before no ticed, to incorporate so minutely with the water in its na tive state ; it would neither so readily dissolve, nor so easily be divided into different qualities, without the process of washing over. When fuel is scarce for baking the earth, it is broken into pieces of the same size, as mentioned above, and then exposed to the heat of the sun.