10 REPORT—1896. 
which it is necessary for me briefly to describe. An exposed raw surface 
became covered in the first instance with a layer of clotted blood or 
certain of its constituents, which invariably putrefied ; and the irritation 
of the sensitive tissues by the putrid products appeared to me to account 
sufficiently for the inflammation which always occurred in and around an 
open wound during the three or four days which elapsed before what were 
termed ‘ granulations’ had been produced. These constituted a coarsely 
granular coating of very imperfect or embryonic structure, destitute of 
sensory nerves and prone to throw off matter or pus, rather than absorb, 
as freshly divided tissues do, the products of putrefaction. The granula- 
tions thus formed a beautiful living plaster, which protected the sensitive 
parts beneath from irritation, and the system generally from poisoning 
and consequent febrile disturbance. The granulations had other useful 
properties of which I may mention their tendency to shrink as they grew, 
thus gradually reducing the dimensions of the sore. Meanwhile, another 
cause of its diminution was in operation. The cells of the epidermis or 
scarf-skin of the cutaneous margins were perpetually producing a crop of 
young cells of similar nature, which gradually spread over the granulations 
till they covered them entirely, and a complete cicatrix or scar was the 
result. Such was the other mode of healing, that by granulation and 
cicatrisation ; a process which, when it proceeded unchecked to its 
completion, commanded our profound admiration. It was, however, essen- 
tially tedious compared with primary union, while, as we have seen, it 
was always preceded by more or less inflammation and fever, sometimes 
very serious in their effects. It was also liable to unforeseen interruptions. 
The sore might become larger instead of smaller, cicatrisation giving place 
to ulceration in one of its various forms, or even to the frightful destruction 
of tissue which, from the circumstance that it was most frequently met 
with in hospitals, was termed hospital gangrene. Other serious and often 
fatal complications might arise, which the surgeon could only regard as 
untoward accidents and over which he had no efficient control. 
It will be readily understood from the above description that the 
inflammation which so often frustrated the surgeon’s endeavours after 
primary union was in my opinion essentially due to decomposition of 
blood within the wound. 
These and many other considerations had long impressed me with the 
greatness of the evil of putrefaction in surgery. I had done my best to 
mitigate it by scrupulous ordinary cleanliness and the use of various 
deodorant lotions. But to prevent it altogether appeared hopeless while 
we believed with Liebig that its primary cause was the atmospheric 
oxygen which, in accordance with the researches of Graham, could not 
fail to be perpetually diffused through the porous dressings which 
were used to absorb the blood discharged from the wound. But when 
Pasteur had shown that putrefaction was a fermentation caused by the 
growth of microbes, and that these could not arise de novo in the 
