From the 1840s until the early years of this century, the great Real del Monte Mining Company maintained managerial ties with salt works in Mexico. Correspondence between company headquarters in Real del Monte or Pachuca and both Peñón Blanco and Texcoco demonstrates the importance of salt to the milling of silver ore. Indeed, as long as silver-quicksilver amalgamation was the basic reduction process (through the end of the nineteenth century) silver producers at every mining camp in Mexico struggled to provide themselves with an adequate and affordable supply of salt, an ingredient in the milling mix whose importance was just short of that of mercury itself.
From where did that salt come? How was it produced? How much did it cost? To what extent was salt production determined by silver processing? These and other questions, raised by examining documents in mining company archives, are answered by Professor Ursula Ewald of the University of Heidelberg in the book under review. The author makes clear, however, that, while helping ore reduction was an important function for a long time, it was by no means the only use nor the whole story of Mexican salt production and distribution over the past four centuries. She argues that, in its own right, “the production of salt is the only industry of significance surviving from pre-Conquest times to our own days, which can be documented over the centuries” (p. 1). If she does not fully establish that claim against, say, silver mining, Ewald does make a persuasive case for the need to include salt production and distribution in any reasonably complete economic history of Mexico.
Writing without jargon from the perspective of the historical geographer, Ewald presents a survey of solar saltmaking in Mexico, with a particular view to the changes that took place in the industry from the midsixteenth century to the present decade. This is an account not of salt mining but of solar salt production, that is, the extraction of salt from the sea or inland saline waters. After an introduction devoted to the explanation of methodology and sources, the author briefly discusses demand, use, and consumption of salt; the legal and administrative background of the industry; and the geography and technology of saltmaking. Ewald uses seven chapters, out of a total of ten, to discuss saltmaking in various parts of Mexico. She devotes well over half of that to the salinas of Peñón Blanco. The book ends with a short chapter evaluating “the impact of saltmaking and salt marketing on land and people” (p. 202).
The book is obviously unbalanced. Overall, only 218 of its total 480 pages are text. The rest contains end notes, glossary, bibliography, tables, figures, and index. Fifteen maps fill a pocket inside the back cover. As noted, nearly half of the text itself deals with the salt works of Peñón Blanco. The importance of those works to the Mexican salt industry at any time in the last four centuries goes a long way toward justifying that heavy emphasis. The relative availability of documentation completes the explanation of the author’s concentration.
This account and the historical survey of the Mexican salt industry seem, perhaps necessarily, based on sparse evidence. In her discussion of sources, Ewald stresses the range available to the scholar but at the same time honestly points out the gaps in official papers, descriptions by observers, statistics, and business records. With due caution, then, the historian and social scientist alike can gain a great deal from Ewalds work. Her information about the manufacture and marketing of salt, as well as about those who did the work and organized the business, is strong when her sources permit. Her insights into saltmaking and its importance to the Mexican economy and culture are stimulating. Despite the documentary curtain, Ewald lifts some of the obscurity from the very old salt industry of Mexico.