Traces of the Past: Unraveling the Secrets of Archaeology through Chemistry. Joseph B. Lambert. xvii + 319 pp. Helix Books/Addison-Wesley, 1997. $30.
The author envisions chemistry as the constant companion to archaeology, and he seeks to demonstrate the debts owed by archaeology to chemistry and materials science. This remarkable work has a "Holmes and Watson" quality—the cooperative sleuthing by archaeologist and physical scientist who, as collaborators, enlighten us about our human ancestors, their cultures and behaviors.
This delightfully compelling, clearly written and profusely illustrated volume of case studies centers on two themes: "the chemical development of the materials of daily life—from pottery to metals and from beer to paper—and the chemical analyses of these materials as discovered in the archaeological context." Joseph Lambert, Clare Hamilton Hall Professor of Chemistry at Northwestern University, writes for rather than down to his readers, creating a masterful synthesis that enlightens complex issues so that one does not have to know much chemistry to enjoy this book. Therefore, the volume is a significant primer on basic technologies, chemistry and archaeology.
We are educated with grace and wit, not only by eloquent studies but also by Lambert's own engaging and cogent writing style that informs and enlightens the reader. The author employs data and illustrations derived from the scientific literature but includes others that are unique to this treatise. Both in the text and in the useful, up-to-date bibliography, he cites the research results and publications of colleagues from many disciplines. This compendium of citations forms a veritable "who's who" of leading archaeological scientific investigators.
The logical sequence of eight chapters, which encompass approximately 75 case studies, is augmented by 143 illustrations (16 in full color), 251 references and a detailed 17-page double-column index that serve to make this volume extremely user-friendly. Two charts, "Chemical Timeline" and "Archaeological Timeline," are especially useful. Lambert explicates clearly the role of archaeological chemistry in the analyses of items as diverse as Murex molluscs, Opuntia cacti, the Vinland Map, the crack in the Liberty Bell, the sunken ship Mary Rose, human excrement and decolorizing glass. Methods such as infrared spectroscopy, gas chromatography and scanning electron microscopy are explained clearly in basic terms so that any reader may enjoy this remarkably thoughtful and thought-provoking volume. Lambert's book successfully interweaves elements from the disciplines of chemistry and archaeology. The book has no peer and, therefore, was a gratifying choice as a recent selection of the Natural Science Book Club.
Although fire—pyrotechnology as the initial human manipulation of the natural world—might be a logical starting point, the author commences with stone. He details elemental and isotopic fingerprinting, studies of rock varnish or patina, and the effects of air pollution on lithic materials as he examines flint, marble, obsidian, steatite, turquoise, basalt, sandstone, limestone and calcite. There are notable reviews of the Colossi of Memnon, the Nazca (Peru) Lines and the sources of the stones used to create Stonehenge. Especially valuable is the section on "synthetic stone"—cement and plaster—and Lambert's determination that the early technology of mortar and cement set the stage for the development of complex technologies, including those used in the making of pottery, glass and metals.
He reminds the reader that earth both "contains and conceals," so that it is the task of the archaeologist and scientist to extract salient data and interpretations. The analysis of phosphorus, organic residues, skeletal silhouettes and soil stratigraphy are among the topics reviewed. Some of the sites used as examples are Fengate, Runnymede, Fort de Chartres (Illinois), Roman Verulaminum (London) and Yagi (Japan). Lambert concludes that "chemical fingerprinting of human activities by soil analysis is an evolving field." He also provides an examination of petrology and a review of pottery—its basic chemistry, forming techniques and color variation. Particularly enlightening are the distinctions made among earthenware, stoneware and porcelain, the techniques used to produce Greek black-and-red figure decorations, the differences among Hispano-Moresque, Delft and majolica ceramics, and a consideration of the imperial Chinese kilns at Jeingdezhen.
Lambert's essay on color includes explanations and examples of special interest to both inorganic and organic chemists. He explains the distinctions between dyes and pigments and direct and fugitive dyes, and clarifies concepts about mordants, solvents and coloring materials. Among the noteworthy examples are Egyptian cobalt blue, Tyrian purple, Maya blue, India (actually Chinese) ink, blue-and-white and Sang-de-boeuf porcelains, analine purple and synthetic indigo (the latter used for "blue" jeans). In the chapter on "glass" the author describes selected glass compositions from a larger universe, emphasizing the properties of modifiers, stabilizers and decolorants, and forming techniques. He posits a probable scenario that the chemistry of pottery led to that of glazes, but that it was early metallurgy that led to glass manufacture. The description of Egyptian faience (a glazed quartz) is enlightening, and Lambert demonstrates that the process of enameling was hybridized from glass and metalworking technologies by the Egyptians. In addition, Roman, Islamic and Celtic contributions to glass technology are reviewed, and the Portland Vase, famille rose, and famille verte glass are considered, as are the distinctions between inglaze and underglaze.
Lambert moves on to advanced chemistry as he considers analyses of total material by infrared spectroscopy or nuclear magnetic resonance, separation by gas chromatography and identification by mass spectrometry. The topics covered include analyses of food, such as beer, wine and chocolate; fibers and textiles, including hides, skins and other animal parts; wood and other plant remains; and natural products, such as petroleum, bitumen, asphalt, jet, tar, pitch, resin and amber. The case of the controversial Vinland Map, recently "rehabilitated by science after being condemned by science," is reviewed, and he elaborates on an example of linguistics supported by chemistry in his summary of cacao residue found in a Maya ceramic vessel decorated with a glyph. Furthermore, the use of chemistry in artifact preservation and conservation issues in nautical archaeology are reviewed in the context of two ships—the Swedish Wasa and the English Mary Rose. Lambert correctly asserts that "the world of organic chemistry is enormous, but it has only begun to impinge on archaeology."
In considering metals, Lambert has synthesized a vast body of scientific literature. His selected topics include native metals and forming techniques, in which he views smelting as "an intellectual and technical landmark of the human race." He conjectures that metallurgy was discovered through the process of the casting of native copper and through pottery technology. He goes on to review the discovery of bronze and independent developments in Central Asia, East Asia, West Africa and western South America, and he explains the production processes for tin, lead, zinc, gold and silver, the reason for the crack in the American Liberty Bell, ancient coinage debasement and coin forgeries. The advent of the Iron Age and the types of iron and steel are documented, and distinctions are made between wrought iron and wootz steel. He includes clear summaries about tumbaga, brass, bronze and gunmetal.
Lambert's final chapter is a masterful synthesis in which he considers the human body as a "library of organic compounds that leave residues." Through the use of isotopic analysis we learn about topics as diverse as fractionation, bone collagen, the presence of C3 and C4 in plants (which include maize and beans), and trace elements in the diet. The list goes on to include lead and iron as health issues, nitrogen and fluorine dating (the Piltdown Hoax is briefly elaborated), organic molecules, scatochemistry (the chemical analysis of coprolites), stereochemistry (arrangement of atoms in a molecule) and thanatochemistry (the chemistry of death), as well as the uses and abuses of amino acid racemization. He also considers chronology (human evolution) derived from electron spin resonance and thermoluminescence, the analysis of blood (genetic markers, genetic distance, human-migration routes and DNA studies), and mitochrondrial Eve. He writes that "applications of molecular biology to archaeology are still embryonic and will both enjoy expansion and suffer limitations as new data are obtained."
In this highly recommended volume Lambert musters the hard sciences of chemistry and biochemistry to bear on the so-called soft sciences of archaeology and anthropology, and demonstrates simultaneously that chemistry is both an analyst of human culture and one of its primary creators. Human beings are not just "tool-makers or tool users," but, in his words, are "chemical animals" because they improve tools by chemical modification, hence, people became the "molecular transformers" of their surroundings. He has condensed a vast subject and is indeed, as one colleague has stated, "a gifted scientist and a born teacher."—Charles C. Kolb, Preservation and Access, National Endowment for the Humanities