[525] “The Frangipani a third time acquired lands in the kingdom of Naples. When they possessed in Maremma di Roma, Tolfa, Castello, and a jurisdiction which brings at present eighty thousand crowns annually to the Church, it happened that a son of Paul di Castro, a celebrated doctor, and a vassal of these lords, who had been many years a slave in Turkey to an alum-merchant, returned free to his own country; and observing that in the territories of Tolfa there was abundance of alum mineral, he gave notice of it to Lodovico Frangipani, his lord, and was the cause of greatly increasing his revenues. Pope Paul II., however, pretending that the mineral belonged to the Apostolic See, as supreme lord of the fief, and not being able to persuade Lodovico to give it up to the Church, he declared war against him, but was vigorously opposed by Lodovico and his brother Peter, lords of Tolfa, assisted by the Orsini their relations; so that the Pope was obliged to bring about an accommodation with them by means of king Ferrante I., and to pay them as the price of Tolfa sixteen thousand crowns of gold, of which Lodovico gave twelve thousand to the king, and was invested by him in the lordship of Serino in the year 1469.”
[526] Ferbers Briefe über Welschland, p. 246.
[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.