In 1828 he performed successfully the most difficult and dangerous operation known to surgery. A clergyman called upon him to remove an enormous tumor in the neck, in which were imbedded and twisted many of the great arteries. In this operation it became necessary to take out entire the right clavicle or collar bone, to lay bare the membrane which surrounds the lungs, to search for and dissect around the arteries which ran through the tumor, to make forty ligatures, and to remove an immense mass of diseased matter. This terrible operation had never been attempted before, and was performed by Dr. Mott without the aid of chloroform; yet it was done so skillfully that the patient survived it, and in 1865 was still living and discharging his ministerial duties. It was thirty years before it was attempted again in any part of the world. It was a great triumph of the genius of the operator, and won him praises from men of science in all countries.
In 1821 "he performed the first operation for osteo-sarcoma of the lower jaw. In 1822 he introduced his original operation for immobility of the lower jaw. He was the first surgeon who removed the lower jaw for necrosis, and the first to tie successfully the primitive iliac artery for aneurism. Other of his original operations were cutting out two inches of the deep jugular vein, inseparably imbedded in a tumor, and tying both ends of the vein, and closing, with a fine ligature, wounds of large veins of a longitudinal or transverse kind, even where an olive-sliced piece had been cut out."
It was invariably his practice before attempting an operation on a living subject to perform it on a dead body, and by the most minute and patient examination to render himself absolute master of the anatomy of the parts to be operated upon. He was a thoroughly conscientious man in the exercise of his profession, and was always on his guard to resist that greatest danger of the skillful surgeon—the temptation to use the knife needlessly. It was his practice to investigate his cases thoroughly, and never to use the knife unless his judgment was satisfied that an operation