Andreas Vesalius, the Reformer of Anatomy

by James Moores Ball

From his own writings and from the manuscript notes of his loyal student, Vitus Tritonius, a fairly good idea of Vesalius’s teaching can be given. The first act of the young Paduan professor was to improve the course in anatomy. Here, as he had done previously at Louvain, Vesalius discharged the entire duties of the professorship. He acted as lecturer, demonstrator and dissector. Dissatisfied with the ignorant barbers, he ignored them and employed his students as assistants. He resorted to all possible means to obtain anatomical material, much of which was secured by stealth.

The aula in which Vesalius conducted his course was built of wood and was capable of holding five hundred persons. In the centre of the room was a table under which was a receptacle containing bones and joints. An articulated skeleton was placed in an upright position at one end of the table. In this elegantly appointed room, before an audience of distinguished laymen and students, the instruction in anatomy was given. The course was a strenuous one, occupying practically the entire day for a period of three weeks, and comprising not only human but also much comparative anatomy. The vivisection of dogs, pigs, and rarely of cats, was a regular part of the course. Drawings were used to elucidate the relations between the skeleton and the soft parts; and frequently Vesalius marked the outlines of the joints upon the skin of the subject. He also marked the cranial sutures with ink. His anatomical charts were the work of his own hand; at times he drew the pictures in the presence of his audience. His dissections were made with extreme neatness and dexterity. He used but few instruments and these were of the simplest kind: knives of different shapes, hooks, cannula, catheter, sounds, bristles, hammer, saw, needles, thread and a sponge. Forceps and injection apparatus were not used; he rarely used scissors. Much of the actual separation of tissues was done by the aid of the finger-nails. A vivisection board completed the list de instrumentis quae anatomes studioso debent esse ad manum.

Let us now follow one Vesalius’s public courses in anatomy. It is the month of December, in the year 1537. The report has spread that the young Belgian professor will begin his course. Long before the hour set for the lecture, every available seat has been taken and many persons are standing. An audience comprising the professors of the University, the students of medicine, officials of the city of Padua, and learned persons of all ranks, including members of the clergy, numbering more than five hundred persons, has assembled to do honor to the professor of anatomy.

Vesalius comes into the arena and walks to the table which is closely surrounded by his auditors. He wastes no time; after a few preliminary remarks on the importance of anatomy and the methods of acquiring a knowledge of this science, he launches into the practical demonstration. After rapidly pointing out the divisions of the body, and demonstrating the skin, joints, cartilages, ligaments, glands, fat and muscles, he passes to the more complex parts, all of which are shown upon the skinned body of a dog or of a lamb, in order to conserve the human material. Now the human cadaver is placed on the table; all eyes are turned upon it, for such a demonstration occurs only at long intervals. Vesalius speaks first of the difference in the structure of joints at different ages and in different sexes, illustrating his remarks by means of drawings and by an abundant supply of bones of man and of the lower animals.

Now comes the dissection. This is made rapidly and in regular order. Its course depends upon the amount of material at hand; if the professor resorts to two bodies, as in the year 1538, the demonstration is handled in grand style. Vesalius uses the first body for a comprehensive examination of the muscles, ligaments and viscera; whilst the second cadaver is devoted to the relations of the veins, arteries, nerves and viscera. The text of the Fabrica is written according to this plan of public dissection.

At times Vesalius attempted to teach the whole of anatomy on one cadaver. In this event, osteology was followed by the dissection of the abdominal muscles layer by layer, the demonstration closing with an examination of the entire contents of the abdomen. The pelvic organs were reached by incision and separation of the symphysis pubis. If the cadaver was that of a female, the dissection began with the mammary glands and then passed to the inferior venter. In pregnancy the foetal membranes were removed intact, and were placed in a vessel filled with water. The foetus was opened and its anastomosing vessels were found. For demonstrating the cotyledons, the uterus of a sheep or goat was used. After the thorax had been raised by means of a log or brick, Vesalius passed to the face and the anterior part of the neck, freely exposing the muscles on one side and the vessels and nerves on the other. Then followed the unilateral preparation of the muscles of the shoulder and back, then those of the mouth, which were approached by means of division of the lower jaw; and, finally, the pharynx and the larynx were exposed. The rectus anticus muscle was next brought into view, whereupon Vesalius detached the head from the vertebral column. Decapitation was followed by an examination of the cranium; the skull-cap was sawed and the brain was dissected in its natural position. Then came the examination of the eye, which Vesalius dissected in two ways: either by a complete section, or layer by layer from without inwards.

The ear and the cavities of the frontal and sphenoidal bones were next opened, provided these bones were not needed for the setting up of a skeleton. Finally he took up the extremities, demonstrating the muscles of an arm and a leg on one side, and the nerves and vessels on the other. The anatomy lesson ended with the introduction of numerous vivisections.

Vesalius could not entirely escape disputations, but he gave to them a close anatomic basis. Theoretical physiology was repugnant to him; for him physiology was not speculation but the sequel of anatomic research. If he at times gave free reign to his views, he indicated them as mere theories. He did not ignore pathologic conditions, but he handled them as briefly as possible. Fearing to tire his audience with too much variety, he confined his students closely to the structure of the human body.

The merit of Vesalius’s public dissections, and the impression which they made upon his auditors, can be appreciated only by comparison with similar demonstrations made by his predecessors. The large and enlightened audience remained day by day for a period of three or four weeks. He says not a word about the physical and mental strain incident to such a strenuous course, in which his entire time was employed. The courses brought great financial profit to the professor.

On two occasions, probably in the years 1539 and 1540, Vesalius was called from Padua to Bologna to conduct public dissections. This was a great honor, for Bologna was the city in which Mondino had revived the practical teaching of anatomy. These courses were conducted by Vesalius in a wooden building erected for that particular purpose. Here, as in Padua, the professor acted as demonstrator and lecturer, remaining in this ancient city for a period of several weeks. On the first occasion he was supplied with three human bodies and was enabled to handle the subject in grand style. At the first séance he engaged with the celebrated Professor Matthaeus Curtius, whose acquaintance he had made in 1538 while on a vacation trip, in a deep study of the question of venesection. Before a large and select assembly he demonstrated in all three bodies that Galen’s description of the vena azygos was incorrect. On the second convocation Vesalius seems to have disposed of more bodies. He reviewed Galen’s work on the joints, and by numerous specimens, which were prepared by the students, he demonstrated the difference in the ancient knowledge of the skeleton. On this occasion he undertook the complete dissection of an ape and presented its skeleton, as well as that of a man, to Professor John Andreas Albius, who held the chair of Hippocratic medicine in Bologna.