Their study of medicine was not without lasting accomplishment, however. They laid down the indications and the dosage for opium. They used iron with success, they tried out many of the bitter tonics among the herbal medicines, and they used laxatives and purgatives to good advantage. Down at Montpellier, Gilbert, the Englishman, suggested red light for smallpox because it shortened the fever, lessened the lesions, and made the disfigurement much less. Finsen was given the Nobel prize partly for re-discovery of this. They segregated erysipelas and so prevented its spread. They recognized the contagiousness of leprosy, and though it was probably as widespread as tuberculosis is at the present time, they succeeded not only in controlling but in eventually obliterating it throughout Europe. It was in surgery, however, that the greatest triumphs of teaching of the medieval universities were secured. Most people are inclined to think that surgery developed only in our day. The great surgeons of the thirteenth and fourteenth centuries, however, anticipated most of our teaching. They investigated the causes of the failure of healing by first intention, recognized the danger of wounds of the neck, differentiated the venereal diseases, described rabies, and knew much of blood poisoning, and operated very skilfully. We have their text-books of surgery and they are a never-ending source of surprise. They operated on the brain, on the thorax, on the abdominal cavity, and did not hesitate to do most of the operations that modern surgeons do. They operated for hernia by the radical cure, though Mondeville suggested that more people were operated on for hernia for the benefit of the doctor's pocket than for the benefit of the patient. Guy de Chauliac declared that in wounds of the intestines patients would die unless the intestinal lacerations were sewed up, and he described the method of suture and invented a needle holder. We have many wonderful instruments from these early days preserved in pictures at least, that show us how much modern advance is merely re-invention. They understood the principles of aseptic surgery very well. They declared that it was not necessary "that pus should be generated in wounds." Professor Clifford Allbutt says: