[506] [This cannot be correct; for Geber, who is supposed to have lived in the eighth century, was acquainted with three kinds of it, and describes the method of preparing burnt alum.] [507] Joh. Serapionis Arabis de simplicibus medicinis opus, cap. 410. [508] Reisebeschreibung, ii. p. 408, 409. [509] This singular appellation occurs in Valentini Historia Simplicium, and several other works. [510] Jul. Cæs. Scaligeri Exot. exercitat. Franc. 1612, 8vo, p. 325. [511] I shall here take occasion to remark, that schist seems to have been employed for making alum in the time of Agricola, as appears by his book De Ortu et Causis Subterraneorum, p. 47. [512] Mercati, Metallotheca, p. 54. [513] Pyrotechnia. Ven. 1559, 4to. [514] Leibnitii Protogæa, p. 47. [515] Bellonii Observationes, cap. lxi. [516] “In Phocis, which lies close to Ionia, there is a mountain abundant in aluminous mineral. The stones found on the top of this mountain are first calcined in the fire, and then reduced to powder by being thrown into water. The water mixed with that powder is put into a kettle; and a little more water being added to it, and the whole having been made to boil, the powder is lixiviated, and the thick part which falls to the bottom in a cake is preserved; what is hard and earthy is thrown away as of no use. The cake is afterwards suffered to dissolve in vessels for four days; at the end of which the alum is found in crystals around their edges, and the bottoms of them also are covered with pieces and fragments of the like nature. The remaining liquor, which at the end of four days does not harden, is poured into a kettle, more water and more powder are added to it, and being boiled as before, it is put into proper vessels, and the alum obtained in this manner is preserved as an article very necessary for dyers. All masters of ships bound from the Levant to Europe, consider alum as a very convenient and useful lading for vessels.... In the reign of Michael Palæologus, the first emperor of his family, some Italians requested a lease of that mountain, for which they promised to pay a certain sum annually.... The Romans and the Latins built Phocæa Nova on the sea-shore, at the bottom of that mountain which lies on the east side of it. On the west it has the island of Lesbos, on the north the neighbouring bay of Elæa, and on the south it looks towards the Ionian sea.”--Ducæ Historia Byzantina. Venet. 1729, p. 71. [517] The alum of Smyrna is mentioned by Baumé in his Experimental Chemistry, i. p. 458. [518] Some account of other Eastern alum-works is contained in a treatise of F. B. Pegolotti, written in the middle of the fourteenth century, on the state of commerce at that time, and printed in a book entitled Della decima e di varie altre gravezze imposte dal commune di Firenze. Lisbona e Lucca, 1765, 4to, 4 vols. It appears from this work, that in the fourteenth century the Italians were acquainted with no other than Turkish alum.