This is a thorough piece of work, the outcome of a decade of research by Dr. Lang on mercury mining and supply in New Spain—an important matter, since most silver produced in colonial Mexico was drawn from its ores by amalgamation. Earlier research has suggested close connections between mercury supply and silver production (for instance, the drop in silver output in the mid-seventeenth century coincides with shortage of mercury), but nobody before Lang has made a complete investigation of mercury supply.
There were, naturally, attempts to find and exploit mercury deposits in Mexico itself. These are recounted at length by Lang. They failed, he tells us, because the deposits, although numerous, were of generally poor quality at shallow levels, and because the crown could not be persuaded to finance thoroughgoing development of the deposits that would have revealed richer ores at greater depths. So most quicksilver for Mexico came from the two great mercury centers located elsewhere in the Spanish Empire: Almadén in Spain and Huancavelica in Peru. Substantial quantities also arrived on occasion from Idrija in Slovenia, and trivial amounts were bought from China. The section of the book describing these sources is its greatest strength. Lang has much to say on them that is not to be found in A. Matilla Tascón’s work on Almadén or Guillermo Lohmann Villena’s on Huancavelica.
The book’s main thesis is that the financial and administrative ineptitude of Spanish government rather than technical problems (though these had their effect) was responsible for inadequate supply of mercury to Mexico in the seventeenth century. On the evidence presented this is certainly a persuasive argument. The government was fully aware that mercury was needed to produce silver. But supply of mercury was denied the priority it should logically have had. The goose that laid the silver egg was, if not killed, at least starved of its basic sustenance. Failure to pay the Fuggers for mercury produced led to their abandoning Almadén in 1645. For the rest of the century, the Councils of the Treasury and the Indies squabbled over administration of the mine, with disastrous results. There was not even money for carts to carry Almadén mercury to Seville for shipment.
Dr. Lang’s book will be of concern to all economic historians of colonial Mexico. It is a substantial addition to our general knowledge of seventeenth-century New Spain. We shall be fortunate if the author can now be persuaded to extend his attention to Peru.