tt PREFACE. t cretus, 3. Lapis, and 4. Metallum. The heteroge neous are divided into compound and mixed mine rals. Nearly at the fame time the famous Cardan wrote a treatife on minerals, which differs principally from that of Agriccia in the faline being leparated from the inflammable bodies. Kentman s work De omni rerum Foflilmm Genere, Gemmis, Lapidibus, Metallis, &c. publifhed in *665, is nearly a tranl'cript of Agricola de Natura Fofliliuin. He adds to it, however, a treatife on petrifactions, entitled Aicyonia, concha:, et alia, quae ex falfo li- quore mans et ex ejus fpumae, cum tenuiflimis fordi- bus permifta concrefcunt. ^ The juftly celebrated botanift Cmfalpinus pub lifhed, in 1602, a work entitled I)e Rebus Metallicis, which contains little deferving of notice. In 1609 Bootius Von Boot publifhed a treatife on precious ftones, in which we find defcribed upwards of fix hundred varieties, having all particular names, a proof of the attention paid to minerals at that early period. . At this time the firft Spanifh mineralogift, Alonzo Barba, a Mexican prieft, publifhed his work De los Metallos. It contains defcriptions, and methods of working minerals. He was the firft who treated of amalgamation. I he great compiler Aldrovandus, in his Mufeum Metallicum, delivered a fyftem of mineralogy extract ed from the writings of Agricola, Cardan, and Caefal- pinus. He was the firft who drew the attention of mineralogifts \