IV. Attitude Toward Magic and Astrology . . . 659

62. The Speculum Astronomiae 692
6^. Three Treatises Ascribed to Albert 720
64. Experiments and Secrets: Medical and Biological . 751
65. Experiments and Secrets : Chemical and Magical . 777
66. PiCATRIX 813
67. GUIDO BONATTI AND BARTHOLOMEW OF PaRMA . . . 825
68. Arnald of Villanova 841
69. Raymond Lull 862
70. Peter of Abano 874
71. Cecco d'Ascoli 948
72. Conclusion 969
Indices :
General 985
Bibliographical 1007
Manuscripts ......••••••■. 1027
PREFACE
This work has been long in preparation — ever since in 1902-1903 Professor James Harvey Robinson, when my mind was still in the making, suggested the study of magic in medieval universities as the subject of my thesis for the master's degree at Columbia University — and has been foreshadowed by other publications, some of which are listed under my name in the preliminary bibliography. Since this was set up in type there have also appeared: "Galen : the Man and His Times," in The Scientific Monthly, January, 1922; "Early Christianity and Natural Science," in The Biblical Review, July, 1922; "The Latin Pseudo- Aristotle and Medieval Occult Science," in The Journal of English and Germanic Philology, April, 1922 ; and notes on Daniel of Morley and Gundissalinus in The English His- torical Review. For permission to make use of these pre- vious publications in the present work I am indebted to the editors of the periodicals just mentioned, and also to the editors of The Columbia University Studies in History, Economics, and Public Law, The American Historical Re- view, Classical Philology, The Monist, Nature, The Philo- sophical Review, and Science. The form, however, of these previous publications has often been altered in embodying them in this book, and, taken together, they constitute but a fraction of it. Book I greatly amplifies the account of magic in the Roman Empire contained in my doctoral dis- sertation. Over ten years ago I prepared an account of magic and science in the twelfth and thirteenth centuries based on material available in print in libraries of this country and arranged topically, but I did not publish it, as it seemed advisable to supplement it by study abroad and of the manuscript material, and to adopt an arrangement by authors. The result is Books IV and V of the present work.
My examination of manuscripts has been done especially at the British Museum, whose rich collections, perhaps be- cause somewhat inaccessibly catalogued, have been less used by students of medieval learning than such libraries as the
X PREFACE
Bodleian and Bibliotheque Nationale. I have worked also, however, at both Oxford and Paris, at Munich, Florence, Bologna, and elsewhere ; but it has of course been impossible to examine all the thousands of manuscripts bearing upon the subject, and the war prevented me from visiting some libraries, such as the important medieval collection of Am- plonius at Erfurt. However, a fairly wide survey of the catalogues of collections of manuscripts has convinced me that I have read a representative selection. Such classified lists of medieval manuscripts as Mrs. Dorothea Singer has undertaken for the British Isles should greatly facilitate the future labors of investigators in this field.
Although working in a rather new field, I have been aided by editions of medieval writers produced by modern scholarship, and by various series, books, and articles tend- ing, at least, in the same direction as mine. Some such publications have appeared or come to my notice too late for use or even for mention in the text : for instance, another edition of the De medicamentis of Marcellus Empiricus by