but it is the contradiction which exists between this testimony, and other well authenticated facts.

Ulloa, Robertson, Raynal, and the writers of the Encyclopédie Méthodique, have not attended to a passage of the Chronicle of Peru, written by Pedro Cieça de Leon. The author who writes with that admirable naïveté, which characterizes all the travellers of the fifteenth and sixteenth century, proposes to give his countrymen an idea of the prodigious wealth of the mountain of Potosi. He was the better enabled to do this from being on the spot in 1549, four years after the first discovery of these celebrated mines. He relates what he saw himself, while Sandoval speaks of a period more than 90 years before. If we are to suspect the numbers of Cieça of error, we ought rather to believe that the error lies on the side of excess; for a traveller who aims at effect, and who hopes to astonish his readers, is naturally inclined to exaggeration. Let us now examine what the historian of Peru relates.* "The wealth of the Cerro de Potosi," says he, "is so much beyond what was ever "seen in former times, that to shew the great"ness of these mines, I shall describe them "as I saw them with my own eyes, when I

* Cieça Chronica del Peru, cap. cviii. (ed". 1554) p. 261.

"passed through Potosi in 1549, at the period "when the Licentiate Polo was Corregidor "of the town. The chests (royal) with three

keys are in the house of this Corregidor. "His Majesty received every week from twenty"five to thirty, and sometimes even forty thou"sand piastres. They complained at that time "that the mines went on poorly, when the "fifth only amounted to 120,000 castellanos "monthly. And yet all this money belonged "to the Christians alone; for the Indians stole "a great deal which was not registered; so "that no where in the world was there ever "so rich a mountain, and no where did any "Prince ever draw so great a revenue from a

single town; for between 1548 and 1551, "the fifth brought into the King more than "three millions of ducats."

To understand this passage, which contains three distinct valuations, we must recollect that the pesos or piastres of that time, and till 1580 at least*, were an imaginary money of 480 maravedis or nearly 13 Reales de plata Mexicana. A marc of silver contained 5 of these piastres. Five piastres made a ducat of 11 reals. According to these data then, reckoning the fifth with Cieça, at 30,000 piastres per week, and

* Garcilasso, Coment. Reales, t. i. in the second preface which bears the title of Advertencias acerca la lengua general del Peru; and t. ii. p. 51.

120,000 castellanos per month, the total produce of the mines of Potosi was (in registered silver), in the year 1549, either 1,549,000, or 1,440,000 marcs. The same produce amounted, according to Cieça, at an average from 1548 to 1551, only to 7,081,000 Mexican piastres of eight reals of plata, equal to 827,000 marcs of silver. This sum forms a singular contrast with the account of Sandoval and Ulloa: but it agrees very well with the fifth of the years when our first table commences. It might remain doubtful whether Cieça speaks really of the totality of the royal duties, levied between 1548 and 1551, or whether he affirms that during that period, the fifth amounted to three millions of ducats per annum. In this last case, the annual produce would have amounted to 21,093,000 Mexican piastres, or 2,481,000 marcs of silver; a very considerable sum no doubt, but still very much below the calculation of Ulloa and Raynal. I am inclined to believe, that the historian of Peru estimates only at three millions of ducats, the sum total of the fifths of the four years; 1st, Because this valuation is more agreeable to the value of the fifth of 1556; 2d, Because Cieça, to give the highest idea of the wealth of the mines, says, that the fifth sometimes amounted to 40,000 piastres, which would give for the maximum of annual produce at that time, a

sum not

above 2,481,000, but hardly equal to 2,065,000 marcs; 3d, Because Garcilasso* relates that about the same period, from ten to twelve millions of piastres in gold and silver of Peru, every year entered the Rio Guadalquivir.

Considering these data of Sandoval as accurate, and combining them both with those of Cieça, and the numbers contained in the official papers published by me, we shall find the following unsatisfactory results for the average annual produce of the mines of Potosi :

From 1545 to 1548 23,284,000 marcs of silver.

The following is the foundation for this calculation. Sandoval and Ulloa estimated the produce of the Cerro de Potosi, between 1545 and 1564, at an average 33,750,000 piastres per annum, or 3,970,000 marcs of silver. Now, we know from the chronicle of Cieça, what was the amount of the produce between 1548 and 1551; the registers of Potosi contain the produce from 1556 to 1564; and supposing for the intermediate period from 1551 to 1556, a decrease in arithmetical progression, it is easy, to find from the 641,250,000 Mexican piastres,

* Garcilasso, ii. p. 52.

or 75,440,000 marcs of silver, stated by Sandoval as the total proportion of the first 19 years, the proportional amount for the small interval from 1545 to 1548.

If we admit, what appears equally improbable, that Cieça indicated the fifth of each of the four years contained in the period from 1548 to 1551, we find, by an analogous operation, that the annual produce of the mines of Potosi amounted,

From 1545 to 1548 to 19,146,000 marcs of silver.

Thus whatever interpretation we give to the passage of the chronicle of Cieça, we shall find it is evident in both hypotheses, that the produce of the first three years differs so much from the following years, that we ought very much to suspect the account of Sandoval. We ought the more to suspect it, as on examining the table of fifths between 1556 and 1789, we discover in this long series of numbers, a law according to which they uniformly increase or decrease. Cieça visited the mines of Potosi, at the period of their greatest splendour; and he expressly says, that he described the mountain as he found it in 1549, "because that "wealth, like every thing human, must vary "in the course of time, either increasing or