Page:The American Cyclopædia (1879) Volume IV.djvu/662

G50 CLAY Constituents, dried at 100 C. Orosi Almerod*. IV.iui.i-, Ardennes. Brierly Hill, near Stourbridge. Schien- dorf. Bertbler. I Bertbler. Bertbler. 1 1 Salvetat. Ilygromet- ric water.. Combined water Silica 15-2 46-5 84-9 8-0 0-48 14-00 47-50 84-87 1-24 0-50 1-00 0-50 16-50 43-79 26-10 6-55 2-00 19 27 2 10-8 68-7 20-7 4-0 1784 45-J5 28-77 7-72 0-47 Alumina Oxide of iron Lime Magnesia. . . The clay beds of the coal formation are exten- sively used at Newcastle for the manufacture of large gas retorts as well as of fire brick. A number of different qualities of clay are found, all of which are from beds overlaid by coal and worked with it. Dr. Richardson gives the following analyses of these varieties : ConitituenU. 1. 2. 8. 4. 5. 6. 7. Silica 51-10 47-55 4S-.'A51-11 71 -23 83-29 69-25 Alumina 81-85 29-50 80-25 80-40 17-75 8-10 17-lM) Oxide of iron. .. Lime 4-lW 1-40 1-54 9-18 1-84 0-71 4-Oti 4-Sl 1-66 1-76 1-91 trace 2 43) 183 2-97 Mof } 1-80 Magnesia Water and or- ganic matter.. 1047 12-01 10-67 12-29 0-94 8-64 7-68 A very singular quality of clay was long ago known in Europe, which produced bricks so light and porous that they floated upon water. The clay was found in Spain, and centuries afterward in Tuscany. Its composition was: silica 65 per cent., magnesia 17, alumina 14, and lime 4. The bricks were remarkably po- rous, light, and such poor conductors of heat that they might be held in the hand by one end while the other was red-hot. Clay of similar properties was afterward met with in Central France, which when mixed with ^ its weight of ordinary clay produced bricks of this character. When submitted by Ehrenberg to microscopic examination, these clays were found to consist of the shelly coverings of infu- soria. Such collections of these microscopic eilicious shells forming beds of clay are not un- common in this country, particularly at the bottom of peat bogs ; and it is highly probable they might be in many places turned to useful account. Ehrenberg, knowing that the clay under Berlin was composed of these organic remains, concluded that it was adapted to this use, which proved to be the case. In the banks of the river Spree it is found sometimes 100 ft. thick, of a light gray color, and almost entirely made up of these little shells, of which it takes no fewer than nine to equal the diame- ter of a human hair. Besides its use for brick, tiles, and earthenware, clay is applied to sev- eral other purposes, as for the manufacture of mosaic tesserae, buttons, and artificial gems ; for the manufacture of alum ; for clarifying sugar by the process called claying ; for pro- ducing a glaze upon paper hangings; for the construction of adobe houses ; and for the full- ing or scouring of woollen cloths. The clay used for this last purpose is called fullers' earth. It is of an unctuous, soft, and dull quality, and is distinguished from other clays by falling to pieces in water with a crackling noise, instead of forming a paste as other clays do. Applied to cloth, it absorbs the oil and greasy matters. Its use has for some time boon gradually giving way to that of soap. Exten- sive as are the uses of clay in the urts, its im- portance in agriculture is still greater, forming as it does the most valuable component of fer- tile soils. CLAY, the name of 16 counties in the United States. I. A central county of West Virgin- ia, intersected by Elk river, and bounded S. E. by Twenty Mile creek ; area, 400 sq. m. ; pop. in 1870, 2,196, of whom 4 were colored. The surface is diversified. The chief produc- tions in 1870 were 39,093 bushels of Indian corn, 11,497 of oats, and 274 tons of hay. The value of live stock was $63,096. Capital, Clay Court House, II. A S. W. county of North Carolina, bordering on Georgia, watered by several streams ; area, about 200 sq. m. ; pop. in 1870, 2,461, of whom 142 were colored. The chief productions in 1870 were 6,061 bush- els of wheat, 79,985 of Indian corn, 14,408 of oats, 4,618 of Irish and 5,507 of sweet pota- toes, 221 tons of hay, and 13,113 Ibs. of tobac- co. There were 587 horses, 945 milch cows, 2,103 other cattle, 3,154 sheep, and 5,376 swine. Capital, Haysville. III. A S. W. county of Georgia, bounded S. by Colomoke creek, separated from Alabama by the Chatta- hoochee river, and watered by its tributaries ; area, about 200 sq. m. ; pop. in 1870, 5,493, of whom 2,849 were colored. The Fort Gaines branch of the Southwestern railroad terminates at the county seat. The surface is level and the soil fertile. The chief productions in 1870 were 85,014 bushels of Indian corn, 18,124 of sweet potatoes, and 3,220 bales of cotton. There wore 875 horses, 845 milch cows, 1,549 other cattle, and 4,281 swine. There were 4 carriage factories and 1 flour mill. Capital, Fort Gaines. IV. A N. E. county of Florida, bounded E. by St. John's river, and watered by its affluents and by numerous lakes ; area, 430 sq. m. ; pop. in 1870, 2,098, of whom 399 were colored. The Florida railroad passes through the N. W. corner. The surface is level. The chief productions in 1870 were 13,188 bushels of Indian corn, 5,322 of sweet potatoes, 6,690 gallons of molasses, and 65 bales of cotton. There were 130 horses, 1,238 milch cows, 2,620 other cattle, and 1,988 swine. Capital, Green Cove Springs. V. An E. county of Alabama, recently formed from portions of Randolph and Talladega countios, drained by tributaries of the Coosa and Tulln- poosa rivers; area, about 700 sq. m. ; pop. in 1870, 9,560, of whom 737 were colored. The soil is well adapted to agriculture. The chief pro ductions in 1870 were 38,422 bushels of wheat,