Jean D. Portell, & Alan J. Neumann,
R. BruceHoadley. Identifying Wood: Accurate Results with Simple Tools. Newtown, Conn: Taunton Press, 1990. 223pages, $39.95 hardcover.Mary-Lou E.Florian, Dale PaulKronkright, and Ruth E.Norton. The Conservation of Artifacts Made from Plant Materials. Marina del Rey, Calif.: Getty Conservation Institute, 1990. 332pages, $30.00 papercover.
THE ABILITY to recognize and identify the species of wood used in the construction of tools, dwellings, artworks, and other objects is a requirement for craftspeople, merchants, museum curators, archaeologists, art conservators, and others. Often this ability is acquired through years of practical experience. Technical training in wood identification is still restricted primarily to those in the disciplines of forestry science and botany. Indeed, the available textbooks on the topics of wood anatomy and taxonomy are generally written for an audience with a technical background in basic botany (e.g., H. A. Core, W. A. Cote, and A. C. Day, Wood Structure and Identification ; F. Jane, The Structure of Wood ; A. J. Panshin, and C. deZeeuw, The Textbook of Wood Technology ), although a few are designed and intended for a broader, less technically oriented audience (e.g., A. Constantine, Know Your Woods ; D. Johnston, The Wood Handbook for Craftsmen ; H. L. Edlin, What Wood is That? ).
Many involved in the care of wooden art and structures are already familiar with Understanding Wood (1980), by R. Bruce Hoadley, a professor of wood science and technology at the University of Massachusetts. His latest publication, Identifying Wood, is a companion volume to his earlier book and presents practical, intelligible information for a nontechnical reader with a serious interest in wood structure and identification.
Identifying Wood begins with comprehensible, concise presentations of botanical systematics and taxonomy, plant morphology, wood anatomy, and the properties of wood. Hoadley has distilled the topics to their essentials and explains the data in easy-to-read narratives. Successive chapters offer discussions of sampling wood for identification purposes, macroscopical and microscopical observation of wood samples, practical applications of wood identification, and, of course, comparisons to assist the reader in wood identification. The book concludes with appendixes on special topics, such as atypical wood, examination of single fibers, chemical tests, additional sources of specialized wood information and supplies, and an excellent glossary.
Hoadley emphasizes the use of simple techniques and readily available, low-cost supplies and equipment. He successfully removes the shroud of scientific mystery from the analytical techniques and instrumentation. His claim that “you can learn all the basics of microscope use in a single session” is overly optimistic, but he does reassure the reader that a compound microscope can be used successfully without knowledge of optical physics. The book is illustrated with line drawings and photomicrographs to support the written descriptions. These illustrations are as important to the reader's comprehension as are Hoadley's conversational narratives. Many, such as the series of photomicrographs on pages 88 and 89 comparing the clearest area of a prepared thin section with other areas that are deficient in some way, are very helpful to the novice in wood technology. There are errors in the labels and captions of several illustrations, and the reader should obtain a copy of the “Errata for Identifying Wood” from the publisher.
Since Hoadley's expertise is primarily with North American woods, species from this region are emphasized. His descriptions of specific and diagnostic characteristics of woods are excellent, as are the photomicrographs of each wood species. Unlike other publications on wood identification, Hoadley does not present a “key”—descriptive couplets of unique features that lead to identification. His book can help someone to confirm that a specimen is, for example, American beech rather than sycamore, but anyone attempting to identify an unknown wood will have to consult other texts. Some tropical and exotic woods and “atypical woods” (e.g., cork, bamboo, and rattan) are mentioned, as are guidelines for identifying decayed wood and charcoal, but the reader will have to research these topics in other sources for detailed information. There is a good bibliography, although additional references for identifying foreign and deteriorated woods would be useful to conservators.
Hoadley's new book is an excellent resource for conservators. If offers comprehensible discussions of technical subjects, such as comparative wood identification and techniques of wood sampling, and it provides many other sources of information on wood and wood identification.
Another valuable addition to the conservator's reference library is the recent publication from the Getty Conservation Institute, The Conservation of Artifacts Made from Plant Materials, by Mary-Lou E. Florian, Dale Paul Kronkright, and Ruth E. Norton. This book evolved from the class notes of three instructors of a course held at the Getty Conservation Institute in 1987 and is intended as an “informational reference source for practicing conservators.” Much of the material presented has been compiled from a great variety of sources that are not readily available to practicing conservators. The authors describe many types of plant materials, how they are used by native peoples around the world, and how plant materials degrade under various environmental conditions. General and specific recommendations are provided for the care and repair of artifacts made from plant materials.
In the first chapter, Mary-Lou E. Florian provides a condensed discussion of general plant anatomy and taxonomy pertinent to identifying unknown vegetative material and to understanding the nature of artifacts containing materials derived from plants. Her summary of plant anatomy is more detailed than Hoadley's but lacks informative illustrations of the quality that would be an asset to most conservators. The reference bibliography at the end of the chapter should be upgraded with current references on plant anatomy and morphology (e.g., A. Fahn, Plant Anatomy ; H. Bold, Morphology of Plants and Fungi ; and new editions of C. Metcalfe and L. Chalk's volumes on the anatomy of monocot and dicot plants). Florian's description of plant classification is extremely brief and, by her own admission, based on an older system. Hoadley's discussion of plant systematics and taxonomy is more current and understandable. For example, the term Thallophyta (referring to all algae, bacteria, and fungi), though still used by many botanists, is archaic; current systematic schemes recognize different kingdoms for these organismic groupings. Conservators should consult recent texts on plant systematics and taxonomy (e.g., S. Jones and A. Luchsinger, Plant Systematics, 2d ed., ).
Florian follows the botanical introductions in chapter 1 with a chapter on techniques employed in studying plant materials from artifacts. She describes how to sample material and prepare specimens for microscopical examination. This discussion could be expanded to include newer methods, such as employing Azure B and Sudan Black B dyes as analytical tests or the use of differential interference contrast microscopy as an analytical tool, as well as modifications of older techniques, such as Hoyer's mounting medium for water-based semipermanent microscope slides (W. Jensen, Botanical Histochemistry ; and J. Berlyn and J. Miksche, Botanical Microtechnique and Cytochemistry ). Florian does point out, however, the importance of using reference samples of plant materials when studying unidentified materials. She includes black-and-white photomicrographs to illustrate her topics, but they are not adequate for use as references; nor does she suggest where a conservator might obtain reference samples or expert assistance. Although some attention is given to stem wood (and to its differentiation from branch and root wood), a welcome emphasis is placed on the materials less often described elsewhere. For example, in a six-page section, plant hairs are differentiated, and an identification key for them is included. Animal protein fibers are also outlined, with a key to their identification, so that they may be distinguished from plant fibers similarly employed as thread and cordage.
The third chapter, by Ruth E. Norton, is an extensive survey of how plant materials have been used to create artifacts. General processing procedures of the raw materials are briefly described, followed by a more detailed discussion of construction techniques accompanied by diagrams of interworking elements. (The drawings for fig. 3.9 (a) and (c) appear to be reversed.) The bulk of the third chapter discusses artifacts according to the catagories of plant organs used to create them. As Norton states, the topic is too vast to be covered comprehensively; her focus is on artifacts from the Pacific and Southeast Asia, with occasional mention of objects from other regions. Even so, the omission of any discussion of pigments (as opposed to dyes) derived from plants is surprising. Many African peoples pulverized wood (especially Baphia nitida and several species of Pterocarpus) to produce red and brown pigments with which they decorated many things, including wood carvings and basketry. Plant fiber pigments such as “camwood” and “barwood” are not mentioned anywhere in the narrative. Yet conservators should be alerted to the need to distinguish them from the visually similar red ocher pigments because the botanical pigments' colors (largely due to extractives) will bleed upon exposure to some solvents.
In chapter 4, Dale Paul Kronkright presents a thorough overview of deterioration processes and their effects at the molecular and cellular levels. Using information from a great variety of sources, he gives basic information about the characteristic physical, chemical, mechanical, and biological alterations that artifacts undergo. He also points out that cultural uses and post-collection handling can leave traces that additionally affect an artifact's present condition. Kronkright's compilation is an important resource for practicing conservators, and an understanding of the concepts he sets down can significantly influence treatment decisions. The addition of a few (macroscale) photographs to illustrate some of the effects he describes would have helped to relate the technical explanations to observed artifact conditions.
The final chapter by Norton and the four brief appendixes that follow deal with specific methods to conserve artifacts made from plant materials. Norton describes the two primary functions of the conservator as preservation and restoration and reminds the reader that ethical considerations must figure in any plan for care. Techniques for labeling, wrapping, storing, and exhibiting are also rightfully concerns of the conservator, even if others will apply them, and these are summarized. Pest management and transportation are critically important, and the reader is referred to up-to-date publications on these topics. Conservation documentation is covered more fully, with detailed recommendations. Regarding repair methods, chapter 5 is uneven and will be far more useful to those who treat basketry than to those who repair carved wood. For example, “patches” (used on interworked fiber constructions) are indexed and described at length, whereas “fills” or “fillings” (appropriate for solid wood artifacts) are neither indexed nor described in detail. One valid form of cosmetic repair of checked wood is omitted: a fill can be adhered along only one side, leaving a narrow crack to accommodate future dimensional changes caused by fluctuations in humidity. The two-page appendix 3, “Characteristics of Adhesives,” contains a brief list of additional information sources but ignores the books written by adhesives scientists, such as the comprehensive Handbook of Adhesives, edited by Irving Skeist, 3d ed. (1989).
With its primary focus on the cultures of North America, Oceania, and Southeast Asia, The Conservation of Artifacts Made from Plant Materials is an important contribution. A wealth of useful information is supplemented by the extensive bibliographies that accompany each chapter. The conservation of what are sometimes termed “ethnographic” material cultures is less advanced than the conservation of “Western” and “Oriental” material cultures, perhaps because artifacts from the former are so often made from plant (and animal) species of very local availability. This book will go far to inform conservators about such indigenous materials and how they have been skillfully fashioned into the often very fragile artifacts that we are now charged with preserving. Many of the recommended repair materials and methods can be expected to be modified or supplanted as conservation practices continue to develop, so the reader would be wise to judge these carefully before applying them. The quantity of pertinent information that is presented about plant materials, their traditional uses, their deterioration, and recommendations for their care makes this new reference publication an essential resource for practicing conservators. The book's sewn binding holds up to repeated use and the wide page margins invite annotating.
Until now, clear directions that enable anyone to observe and understand the fine anatomical features by which wood species are distinguished have been lacking. Most publications of botanical information likewise have given relatively little attention to some species that may occur significantly in ethnographic artifacts and to changes in the nature of plant and fibers due to their degradation. The two books reviewed here are therefore important new reference sources. They should help conservators to assess much more accurately the nature, condition, and appropriate treatment of objects made from plant materials.Jean D.PortellJean D. Portell Inc., 13 Garden Place, Brooklyn, New York 11201Alan J.Neumann,Ph.D.Winterthur Museum, Winterthur, Delaware 19735