(13) How do the nerve trunks differ from the fibrous envelope holding together all these structures? (14) Differentiate between the nuclei of the nerve fibres and the nuclei of the nerve sheath. (15) Examine nerve branches of various thicknesses—what do you find the nature of the nerve fibres to be? Do not forget the aniline blue and try other staining fluids. (16) Can you find evidence in the alveoli of other structures besides capillary, membrana propria and salivary cells? (17) How far have you succeeded in following the fine nerve twigs? (18) By all means try different methods, different tissue, and compare the results. See what you can discover by simply teasing material treated with Muller’s fluid, and other stained and treated as I have described. (19) Follow the course of the arteries, and note where the larger vessels pass into the capillaries. A HISTORY OF MEDICINE. BY JOHN BENNITT, M. D., Professor of Principles and Practice of Medicine in the Medical Department of the Western Reserve University, Cleveland, Ohio. [_Continued from page 103._] But the contributions to medicine of all his predecessors dwarf into insignificance when compared to those of Galen—who lived and wrote in the middle of the second century—and whose writings were ultimate authority, until they were attacked and publicly burned in the 16th century by the arch-quack Paracelsus. Galen, although born in Pergamus, in Mysia and living there, was called by the Emperors M. Aurelius, and L. Verus to attend them in the northeastern frontier of Italy, and was for a considerable period of time physician to the emperor, spending a considerable portion of the last half of his life at Rome. He died in Sicily in 201 aet 71 (?) There are ascribed to him 83 treatises on medicine about which there is no question as to their genuineness, 19 that are questionable, 45 undoubtedly spurious, 19 fragments, 15 commentaries on Hippocrates’ works. Besides these, he wrote a great number of works (not all on medicine) whose titles only are preserved, so that altogether it is believed that the number of distinct treatises cannot have been less than 500. These were, on (1) Anatomy and Physiology, (2) Dietetics and Hygiene, (3) Pathology, (4) Semiology and Diagnosis, (5) Materia Medica and Pharmacy, (6) Therapeutics including Surgery, (7) Commentaries on Hippocrates, (8) Philosophical and Miscellaneous. Most of these works are still extant in Greek (in which they were originally written). They have been translated into many modern languages. His works on anatomy and physiology are most valuable. But it is not certain that he ever dissected human bodies. His knowledge he derived from dissecting apes, bears, goats, etc., and his knowledge of physiology from experiments on these animals. His pathology was speculative.