Probably the most important book on medicine that we have from the twelfth century is written by a Benedictine Abbess, since known as St. Hildegarde. She was born of noble parents at Boeckelheim in the county of Sponheim, about the end of the eleventh century. She was educated at the Benedictine cloister of Disibodenberg, and when her education was finished she entered the house as a religious, and at the age of about fifty she became abbess. Her writings, reputation for sanctity, and her wise rule, eminently sympathetic as she was, attracted so many new members to the community that the convent became overcrowded. Accordingly, with eighteen of her nuns, Hildegarde withdrew to a new convent at Rupertsburg, which English and American travellers will doubtless recall because it is not far from Bingen on the Rhine, made famous in the later time by Mrs. Hemans's poem. Here she came to be a sort of centre for the intellectual life of her period. According to traditions, some of which are dubious, she was in active correspondence with nearly every important personage of her generation. She was an intimate friend of St. Bernard of Clairvaux, who was himself perhaps the most influential man of Europe in this century. Her correspondence was enormous, and she was consulted from all sides because her advice on difficult problems of any and every kind was considered so valuable. In spite of all this time-taking correspondence she found leisure to write a series of books, most of them on mystical subjects, but two of them, strange as it may seem, on medicine. The first is called "Liber Simplicis Medicinæ," and the second "Liber Compositæ Medicinæ." These books were written as a contribution of her views with regard to the medical knowledge of her time, but were evidently due, partly at least, to the Benedictine traditions of interest in medicine. Dr. Melanie Lipinska in her "Histoire des Femmes Médicins," a thesis presented for the doctorate in medicine at the University of Paris in 1900, which was subsequently awarded a special prize by the French Academy, reviews Hildegarde's work critically from the medical standpoint. She does not hesitate to declare the Abbess Hildegarde the most important medical writer of her time. Reuss, the editor of the works of Hildegarde as they are published in Migne's "Patrologia," the immense French edition of all the important works of the Fathers, Doctors, and Saints of the Church, says: