60 MINERALOGY. 



Ayres, although these domains may be considered as consti- 

 tuting a part of the Peruvian territory, are not comprehended. 



During a space of ten years, from the commencement of 

 1780 to the end of 1789, the above mines yielded thirty-five 

 thousand three hundred and fifty-nine marks of gold, twenty- 

 two carats fine ; and three millions seven hundred and thirty- 

 nine thousand seven hundred and sixty-three marks of silver*. 

 In the year 1790, the silver mines yielded four hundred and 

 twelve thousand one hundred and seventeen marks of that me- 

 tal ; being an excess of thirty- eight thousand one hundred 

 and forty-seven marks over the average produce of the ten an- 

 tecedent years. 



It would appear that the mines of Mexico are much more 

 produ6tive than those of Peru, since in the above year of 

 1790, which was far from being reckoned one of the best, 

 five thousand and twenty-four marks of gold, and two mil- 

 lions one hundred and seventy-nine thousand four hundred 

 and fifty-five marks of silver, the produce of the mines, were 

 coined in the Royal Mint of Mexico. The proportion of 

 silver was consequently in the ratio of more than five to one 

 greater than that afforded by the Peruvian mines. 



* The mark of gold being estimated at a hundred and twenty-five piastres, and 

 that of silver at eight piastres, the total amount, in sterling money, of the produce 

 of the mines, during the above ten years, will be found to have been of the value of 



HISTORICAL 



