Johann Heinrich Dierbach (1788–1845)

his eighties. In 1835, he married and settled in Paris as a teacher at the Conservatoire des Arts et Metiers, while conducting agricultural experiments with his brother-in-law on an estate in the Alsace, which was sustained economically by revenues from oil-bearing sands. Although McCosh's account of the collaboration with Dumas and the fat controversy with Liebig does not replace that given by F.L. Holmes in his study of Bernard and animal chemistry, he provides a good account of Boussingault's single-minded devotion to unravelling the nitrogen cycle. The book is marred by copious misprints, but is otherwise an exemplary biography. Tracing the life-story of a man who never became a household name, despite his contribution to science, can be difficult. Nevertheless Jochen Keidel, using sources such as city and university records, personal letters, published works, and published critiques by other scholars, has pieced together the absorbing story of the Heidelberg professor, J. H. Dierbach. Against a background of almost continuous financial difficulties and discriminatory uncongenial working conditions, Dierbach, the son of a master-bookbinder, emerged as a first-class classical scholar, a brilliant teacher, a splendid botanist, an experienced and capable pharmaceutist, and a physician who never practised medicine. Keidel reveals the way in which Dierbach sought to present botany as a scientific discipline with up-to-date terminology, although his textbook A guide to the study of botany (1820) caused much criticism of his modernizing efforts. To a pharmacist, Dierbach's Outline ofprescription art is a veritable mine of information on medicine of the time, and includes a survey of contemporary medicines and 227 formulae with relevant therapeutic information and annotations. Keidel discusses classification, theoretical background of formulations, dosage and form of Dierbach's medicine, but he only reproduces two prescriptions in detail, thereby encouraging the reading of Dierbach's original text. The author shows how Dierbach the historian was able to use his broadly spread talents to advantage. Thus he was able to assess authoritatively the ancient physicians and botanists, and one of his works, the Flora mythologica, was considered worth reprinting in 1970. Today, as in Dierbach's own time, there are questions still unanswered. Was Dierbach a skilled compiler whose reassessments based on sound classical and scientific knowledge are of considerable value to science or was his torrent of publications of little value? Keidel's book sympathetically presents a well-researched, well-annotated account of Dierbach's life, times, and work, but he shrewdly leaves the reader to draw …