47. Various kinds of earth. The Puteolan dust, and other earths of which cements like stone are made 288 48. Formacean walls 289 49. Walls of brick. The method of making bricks 290 50. Sulphur, and the several varieties of it: fourteen remedies 291 51. Bitumen, and the several varieties of it: twenty-seven remedies 293 52. Alumen, and the several varieties of it: thirty-eight remedies 294 53. Samian earth: three remedies 298 54. The various kinds of eretria _ib._ 55. The method of washing earths for medicinal purposes _ib._ 56. Chian earth: three remedies. Selinusian earth: three remedies. Pnigitis: nine remedies. Ampelitis: four remedies 299 57. Cretaceous earths used for scouring cloth. Cimolian earth: nine remedies. Sardinian earth. Umbrian earth. Suxum _ib._ 58. Argentaria. Names of freedmen who have either risen to power themselves, or have belonged to men of influence 301 59. The earth of Galata; of Clypea; of the Baleares; and of Ebusus 303 BOOK XXXVI. THE NATURAL HISTORY OF STONES. 1. Luxury displayed in the use of various kinds of marble 305 2. Who was the first to employ marble in public buildings 306 3. Who was the first to erect columns of foreign marble at Rome 307 4. The first artists who excelled in the sculpture of marble, and the various periods at which they flourished. The Mausoleum in Caria. The most celebrated sculptors and works in marble, two hundred and twenty-five in number 308 5. At what period marble was first used in buildings 323 6. Who were the first to cut marble into slabs, and at what period 324 7. Who was the first to encrust the walls of houses at Rome with marble _ib._ 8. At what period the various kinds of marble came into use at Rome 325 9. The method of cutting marble into slabs. The sand used in cutting marble _ib._ 10. Stone of Naxos. Stone of Armenia 327 11. The marbles of Alexandria _ib._ 12. Onyx and alabastrites: six remedies 329 13. Lygdinus; corallitic stone; stone of Alabanda; stone of Thebais; stone of Syene 330