Lydian Stone. 199 Obfervations. *• Bafalt, and certain compact varieties of clay fiate, are what many of the French mineralogifts confider to be Lydian ftone. 2 * Humbold, from a feries of experiments which made on this foflil, aflerts that it contains a por- tlo n of carbone, which is alfo countenanced from 8 eo gnoftic data. _ 3* It is faid to have been firft found in the pro- v, nce of Lydia in Leffer Afia, whence its name. THIRTIETH