The history of commodities has become fashionable. A cursory glance at publishers’ catalogues reveals that in the course of the past few years, historians could choose among a history of cod, the potato, corn, tobacco, coal, and cocoa; studies that followed on the heels of older works on the history of sugar, silk and oil. It is somewhat mysterious why such an outpouring of interest in the history of such commodities occurred, but two developments certainly have favored such a wave: the advent of more transnational approaches to the study of the human past and the rise of cultural history.
Commodity studies now have two new entries: Mark Kurlansky’s Salt: A World History, and Alan Macfarlane’s and Gerry Martin’s Glass: A World History. And there are very good reasons why we should be interested in these studies. Aside from the obvious importance of the two commodities under review, these studies take advantage of the opportunities that a commodity-centered approach allows. They follow their respective commodity from production to consumption, showing how in the process it was transformed, traded and subject to the interests of the weak and the powerful. Both studies are truly global in scope -- they connect developments in many different parts of the world. Moreover, these two books are sweeping in time, dealing with developments during the past two thousand years. Last but not least, they combine fields of historical study that are usually kept separate from one another—the history of food, of agriculture, of industry, of ideas, of technology, of consumption, and of production. Of course, there are still differences: Kurlansky’s orientation is more cultural, anecdotal, and interested in consumption, while Macfarlane and Martin are friends of clearly articulated questions and models, self-confessed structuralists interested especially in the conditions of production. The authors also address different audiences: Kurlansky probably imagines his ideal reader to be a serious amateur cook with an interest in history, while Macfarlane’s and Martin’s audience is the growing crowd of intellectuals concerned with the “Great Divergence.”
What tales do these books tell? Mark Kurlansky’s History of Salt conveys a fascinating story of the role of salt in human affairs during the past two thousand years. He recounts wars fought over the access to salt, chronicles rebellions against greedy rulers asking for exorbitant tax payments on the production or consumption of salt and describes manifold inventions based on salt. The true focus of the book, however, is on the uses of salt in the cuisine of people all around the world, the Roman garum, the Basque cod, the Chinese soy sauce, the Swedish herring, the English ketchup, the Jewish lox, and the Italian Parma. Kurlansky observes that in the days before artificial refrigeration, preserving foods depended almost entirely on salt. Not only did this result in the creation of very salty foods in every culture, but it also meant that food production and human survival depended on regular access to salt. This salt, as he shows, was for most of human history a precious commodity, which, in turn, explains the willingness of rulers to use military power to control and tax it.
The well-written book is a must read for passionate cooks and lovers of salty foods, but less so for students of global history. To be sure, Kurlansky demonstrates that salt and ideas about its uses often traveled far, thus connecting various parts of the globe. He also shows that the ability to preserve food by salting it was one of the preconditions for global trade, migration and warfare. And there are certainly fascinating bits of information in the book—who would have known, for example, that curvy roads in suburban America were built on trails that once upon a time led to salt licks? Who would have known that ketchup started its career as an anchovy sauce? However, as a work of history the book does not entirely succeed, especially because it is never quite clear which question Kurlansky sets out to answer. He does establish that salt was very important to human survival, but that is not exactly news. He also shows that salt turned from a rare and expensive commodity to one that it plentiful and cheap, but again, we did know that. While it is undoubtedly true that lots of interesting developments and events in world history were linked to salt, it is less true that they can best be explained by reference to salt alone. What are causes and what are just mere coincidences? Because Kurlansky presents a myriad of facts in a somewhat arbitrary order, it is difficult to decide which ones matter and which ones do not, since it is unclear which question they should help to answer. What is also lacking are systematic comparisons and quantitative analysis. For example, it would have been interesting to systematically compare salt tax regimes in various parts of the world, information that probably could have been used to say a few interesting things about the nature of particular regimes. Such information is missing. Also, it would have helped to get a sense of the most important salt trade networks and how they changed over time. In the end, we learn very little about the changing nature of the world economy, but a lot about such little known facts as that in the Chinese city of Zigong buses were powered by natural gas derived from salt wells, carrying the gas in “gray bladders on the roof;” that Moe Greengrass on Manhattan’s Upper West Side sells more Nova than lox, and that Germans are the largest single group of foreign tourists in Israel’s Dead Sea resorts. While all of that is interesting, it does not fully take advantage of the analytical possibilities that are inherent in a global commodity chain approach.
Compare that to Alan Macfarlane’s and Gerry Martin’s history of glass. Here, we have a clearly articulated question and a deeply analytical account that seeks to provide answers. The question is, as so often nowadays: Why the West? The “Great Divergence,” Macfarlane and Gerry Martin explain, is rooted to a significant extent in the western ability to make and use glass in ways unlike any other civilization. Macfarlane and Martin argue that without glass, the way of life as we know it could not exist: There would be no electric light (no light bulbs), our homes would be dark and cold without window glass, there would be no modern science (as it depends on glass tools) and even western art as it unfolded since the Renaissance would have been different without access to quality mirrors. Once Europeans mastered glass and combined it with their curiosity about the world, other civilizations were no match. Glass, thus, is at the very core of our civilization.
This “Great Divergence” occurred according to Macfarlane and Martin already two thousand years ago, when the Romans pioneered the manufacturing of superior glass. These glass making skills survived the downfall of the Roman Empire in a few locales, especially in Syria, Egypt and the Eastern Empire, from where migrating craftsmen brought them back into Southern and Northern Europe in the twelfth and thirteenth centuries, for example to Venice and to Bohemia. By the fifteenth century, as a result, “glass had become ubiquitous” in Europe.(p. 26) Glass then became a central ingredient in laboratory science (flasks, telescopes, microscopes), allowing for an explosion of experimental science. At the same time, the spread of glass windows allowed Europeans to develop a different relationship to the natural world, as they experienced the sensation of looking at the word from the inside, experiencing a framed, and thus limited view of nature, encouraging its scientific exploration. Moreover, the mirror helped advance the concept of individualism. Equipped with these cultural proclivities and tools, Europeans could also spectacularly extend the intellectual life of people at their peak knowledge by giving them spectacles that allowed for close study and reading beyond age forty. While Macfarlane and Martin admit that the breakthrough in Europe can be explained in all kinds of ways ranging from its legal traditions to the spread of printing, they conclude that the crucial factor was glass.
Glass also explains the “Great Divergence,” because all these developments so crucial to European “take off” did not occur elsewhere. Though for a few hundred years, the center of global glass making skills was to be found in the Arab world, “Arabic theoreticians […] did not break through into that set of interconnected practices which we call science.” (p. 36) Moreover, in the thirteenth and fourteenth centuries, the Arab glass industry was all but destroyed. Other civilizations suffered from a similar lack of glass: India had very little high quality glass, Chinese glass technology was rudimentary and Japan was not successful at making high-quality glass ubiquitous.
I am not an expert in the history of science nor in the history of the Renaissance, which makes it all but impossible to evaluate some of the large claims the authors make. But I very much appreciate the questions the book asks and how it goes about answering them. It is clear that Macfarlane and Martin draw greatest advantage of the commodity centered approach because it forces them to think comparatively and to think about very large networks. As the authors remark towards the end of their work, the question they pose only emerges if one thinks globally. Without looking at regions of the world outside of Europe, the question of glass does not pose itself and without thinking about large networks the history of glass in a particular European region or country can not be fully comprehended. In fact, if you want to understand Murano (Italy), you need to know about Aleppo (Syria).
While I am largely persuaded by Macfarlane’s and Martin’s approach, some questions still remain. For one, despite their protestations to the contrary, I still see a tension between the book’s repeated insistence that glass was the central factor in explaining the scientific revolution and the Renaissance, and hence the “Great Divergence,” while at the same time arguing that glass was only a necessary, but not a sufficient factor. When they argue towards the end of the book that even if China and Japan would have produced fine glass, the outcome might not have been different, they seem to be undermining their own argument (p. 202). “It is the attitude towards glass which distinguishes the history of glass in Western Europe to its history in Asia,” they argue, but if it is “the attitude” then would we not look for the factors explaining the “Great Divergence” in these “attitudes” (p.14).
Second, I wish Macfarlane and Martin would have engaged competing accounts of the “Great Divergence”—David Landes’, Kenneth Pomeranz’ and Jared Diamond’s, for example. They all provide very different explanations and also very different chronologies, and the authors could have profited from dealing with those.
Third, and related, I am somewhat suspect that the “Great Divergence” can be explained by reference to one core commodity such as glass at all. The above mentioned authors, despite their disagreements, teach us that we need to cast our nets wide, that there is probably not one “golden bullet” answer for what is after all one of the most important question in human history. It seems that we need to think in broader terms about the problem, especially about networks that are not focused on a particular commodity. A commodity centered view of history allows us to “see” and reconstruct certain networks of human interaction, but it is these networks themselves, reaching well beyond a particular commodity and deeply affected by relations of power, that perhaps allow us best to explain the “Great Divergence.”
Both Kurlansky’s study on salt and Macfarlane’s and Martin’s book on glass are fascinating examples of a developing view of history that begins its investigation by looking at things instead of at individuals, groups of people, or states. Such a perspective allows for new and fascinating perspectives on the history of global connections, uneven development and also on many historical questions that traditionally have been investigated in local, regional or national contexts. However, the two studies also show the limitations of such an approach. While they argue that without their respective commodity we could not live (salt) or not live the way we are accustomed to (glass), they tend to underemphasize the fact that there are lots of other things that are essential to life and to our way of life. The history of the world thus is more than the history of one “core” commodity, many of which are necessary but none of them are sufficient to provide an explanation for what animates human history.