ADDRESS. 11 
decomposable substance, the problem assumed a more hopeful aspect. If 
the wound could be treated with some substance which, without doing too 
serious mischief to the human tissues, would kill the microbes already con- 
tained in it and prevent the future access of others in the living state, 
putrefaction might be prevented, however freely the air with its oxygen 
might enter. I had heard of carbolic acid as having a remarkable 
deodorising effect upon sewage, and having obtained from my colleague 
Dr. Anderson, Professor of Chemistry in the University of Glasgow, a 
sample which he had of this product, then little more than a chemical 
curiosity in Scotland, I determined to try it in compound fractures. 
Applying it undiluted to the wound, with an arrangement for its 
occasional renewal, I had the joy of seeing these formidable injuries follow 
the same safe and tranquil course as simple fractures, in which the skin 
remains unbroken. 
At the same time we had the intense interest of observing in open 
wounds what had previously been hidden from human view, the manner 
in which subcutaneous injuries are repaired. Of special interest was the 
process by which portions of tissue killed by the violence of the accident 
were disposed of, as contrasted with what had till then been invariably 
witnessed. Dead parts had been always seen to be gradually separated 
from the living by an inflammatory process and thrown off as sloughs. 
But when protected by the antiseptic dressing from becoming putrid and 
therefore irritating, a structure deprived of its life caused no disturbance 
in its vicinity ; and, on the contrary, being of a nutritious nature, it served 
as pabulum for the growing elements of the neighbouring living structures, 
and these became in due time entirely substituted for it. Even dead bone 
was seen to be thus replaced by living osseous tissue. 
This suggested the idea of using threads of dead animal structures for 
tying blood-vessels ; and this was realised by means of catgut, which is 
made from the intestine of the sheep. If deprived of living microbes, and 
otherwise properly prepared, catgut answers its purpose completely ; the 
knot holding securely, while the ligature around the vessel becomes 
gradually absorbed and replaced by a ring of living tissue. The threads, 
instead of being left long as before, could now be cut short, and the 
tedious process of separation of the ligature, with its attendant serious 
danger of bleeding, was avoided. 
Undiluted carbolic acid is a powerful caustic ; and although it might 
be employed in compound fracture, where some loss of tissue was of little 
moment in comparison with the tremendous danger to be averted, it was 
altogether unsuitable for wounds made by the surgeon. It soon appeared, 
however, that the acid would answer the purpose aimed at, though used 
in diluted forms devoid of caustic action, and therefore applicable to 
operative surgery. According to our then existing knowledge, two essen- 
tial points had to be aimed at: to conduct the operation so that on its 
completion the wound should contain no living microbes, and to apply a 
