[527] “This year (1460) is distinguished by the discovery of alum at Tolfa vecchia, no one there having been acquainted with it till that period: and this happened by means of one John di Castro, who had acquired some knowledge of it from a young man of Corneto, and a Genoese, who had learned in Turkey the whole process of making it. The said John having observed that in the mountains of Tolfa there were undoubtedly veins of alum, he caused some of the earth and stones to be dug up, and the first experiments were made on them at Viterbo in the following manner. The stones were first calcined in a furnace; a large quantity of water was then thrown over them; and when they were entirely dissolved, the water was boiled in great leaden caldrons; after which it was poured into wooden vessels, where, evaporating by degrees, the result was alum of the most perfect kind. Pope Pius II., sensible of the great benefit which might arise from this mineral to the Apostolic Chamber, employed more than eight hundred persons at Tolfa in preparing it.”--Historia della Città de Viterbo, di Feliciano Bussi. In Roma 1742, fol. p. 262. [528] Museo di Fisica, &c. Ven. 1697, p. 152. [529] Viaggi, vii. p. 234. [530] Anno 1458. “Rock alum, which the Greeks call _pharno_, was at this time first discovered by a Genoese in the territories of Volterra, where being boiled and found to be good, it began to be dug up afterwards in many of the mountains of Italy. Till that period the Italians had made no use of mines of this kind; for our alum was all brought from Turkey. The above discovery was therefore a great advantage to us.” [531] An account of this dispute between the Florentines and the people of Volterra may be seen in Machiavelli’s History of Florence, book vii. [532] Rap. Volaterrani Comment. Urbani. [533] De Thermis. [534] Viaggi, iii. p. 117. [535] Ibid. vii. p. 51. [536] De Thermis, p. 293. Tozzetti, iv. p. 186. [537] Nicol. Rodrig. Fermosini Tractatus Criminalium. Lugd. 1670, 2 vol. fol. tom. ii. p. 63. [538] Pyrotechn. p. 31. He says expressly that this was the only alum-work in Europe in his time without the boundaries of Italy. [539] History of Commerce, iv. p. 406. “The manufacture of alum,” says he, “was first found out in England, and carried on with success in 1608. It was supported and patronized in the county of York by lord Sheffield, sir John Bourcher, and other landholders of the said county, to the great benefit of England in general, and of the proprietors in particular, to the present day. King James was a great promoter of this alum-work, after he had by the advice of his minister appropriated to himself a monopoly of it, and forbidden the importation of foreign alum.”