While a hospital interneship is an ideal method of postgraduate training, not more than ten to twenty per cent. of graduates can under present conditions be provided with such interneships. The remaining large majority must depend for their training upon a course of practical study under competent specialists in the various departments of medicine and surgery in a school which is part of a general hospital and dispensary, and provided with all the laboratory facilities for analytic work. The Polyclinic Hospital, with a capacity of three hundred beds, a walking clinic of between fifty thousand and one hundred thousand cases per year, has in addition an ambulance and emergency service covering a district in New York City which includes a population of three hundred and sixty thousand. The acute medical and surgical cases which are gathered up by this vast service are among the most interesting and useful features of its course of instruction.

The entire course of study is divided into the following departments: Clinical medicine and physical diagnosis, diseases of the digestive system, diseases of children, diseases of the throat and nose and of the eye, diseases of the nervous system, general and orthopedic and neurological surgery, diseases of the rectum, genito-urinary surgery, diseases of the skin, diseases of women, obstetrics, radiology, electrotherapy, clinical microscopy, urinary analysis, practical histology, and pathology and bacteriology.

In the department of internal medicine there is a special laboratory for instruction in the examination of stomach contents, alimentary discharges, and the various secretions and excretions. There is a special laboratory in the department of dermatology and in general medicine, while the main laboratory of biology is thoroughly equipped for a

practical training of the practitioner in the use of the microscope and in chemical analysis and the study of the various reactions.

The necessity of dividing the classes into small sections is recognized as the essential feature of thorough postgraduate training, so that those interested in any particular case may come in actual contact with the patients. To this end seven operating and three different medical clinical rooms are often utilized at the same hour. Realizing the greater value of prolonged and continuous attendance, a special course is arranged in which the practitioner resides within the hospital and serves on the assistant interne staff. To the date of this writing, in 1914, approximately twenty-five thousand graduates of medicine and surgery have attended the clinics and courses of study in this institution.

II

LIGATION OF THE EXTERNAL CAROTID ARTERY

My Essays on the Surgical Anatomy and Surgery of the Common External and Internal Carotid Arteries, made public in 1878, established as an accepted operative procedure the ligation of the external carotid artery. Until that date every text-book on surgery in the English, French, or German language advised the application of the ligature to the common trunk, and not to the external carotid, in all lesions within the distribution of the external carotid artery. Within two years after the publication of these essays by the American Medical Association, the text-books and teachers of surgery had condemned the old operation and advised the new procedure.1 My attention was attracted to this subject by a statement made by my teacher in surgery, Professor Frank H. Hamilton, while I was a student in Bellevue Medical College. In advising the application of the ligature to the primitive carotid he gave as the reason that the external carotid artery differed from all the other arteries of body in the wide variations in origin and irregularity of the arrangement and distribution of its branches.

Believing, as I did, that there could be no exception to the law of development, I undertook a careful study of this important vessel, in the course of which I made one hundred

1 Prominent among the great surgeons of his day, and among the first to appreciate the value of this operation, was the late Henry B. Sands, Professor of Surgery at the College of Physicians and Surgeons.

and twenty-one dissections of the surgical triangles of the neck, measuring accurately with rule and pointers the points of origin on the six regular branches-viz., the superior thyroid, lingual, and facial anteriorly, and the ascending pharyngeal, occipital, and auricular posteriorly, from the center of bifurcation of the common trunk and from one another. I proved that this vessel followed the general law of development; that the range of origin of each branch was so limited and the variations from the normal so slight as to offer no difficulty or danger to the application of a ligature at any point in the course of this artery.

Extending my investigations into the surgical history of these vessels, I found that in the entire records of surgery, searched with great care, the external carotid artery alone had been tied for lesions within its distribution only sixtyseven times, with a mortality ratio of four and a half per cent. At the same time I tabulated seven hundred and eighty-nine cases of ligature of the common trunk, of which two hundred and fifty-one were for lesions in the distribution of the external carotid artery, and in every one of which this latter vessel might have been tied. One hundred and eight, or forty-three per cent., died.

Extending these researches to the arch of the aorta, and the other great vessels springing from it, and desiring to test crucially the value of the conclusions arrived at, I entered into competition for the annual prize of the American Medical Association in 1878, and submitted my work as a single essay.

As far as the carotid arteries are concerned, this was the conclusion reached at that period:

The rate of mortality after the ligature of the common carotid artery was forty-one per cent.