ved one of the greatest boons ever
conferred upon humanity. It had long been recognized that, now and
again, a wound healed without the formation of pus, that is, without
suppuration, but both spontaneous and operative wounds were almost
invariably associated with that process; and, moreover, they frequently
became putrid, as it was then called,--infected, as we should say,--the
general system became involved and the patient died of blood poisoning.
So common was this, particularly in old, ill-equipped hospitals, that
many surgeons feared to operate, and the general mortality in all
surgical cases was very high. Believing that it was from outside that
the germs came which caused the decomposition of wounds, just as
from the atmosphere the sugar solution got the germs which caused the
fermentation, a young surgeon in Glasgow, Joseph Lister, applied the
principles of Pasteur's experiments to their treatment. From Lister's
original paper(*) I quote the following: "Turning now to the question
how the atmosphere produces decomposition of organic substances, we find
that a flood of light has been thrown upon this most important subject
by the philosophic researches of M. Pasteur, who has demonstrated by
thoroughly convincing evidence that it is not to its oxygen or to any of
its gaseous constituents that the air owes this property, but to minute
particles suspended in it, which are the germs of various low forms
of life, long since revealed by the microscope, and regarded as merely
accidental concomitants of putrescence, but now shown by Pasteur to
be its essential cause, resolving the complex organic compounds into
substances of simpler chemical constitution, just as the yeast-plant
converts sugar into alcohol and carbonic acid." From these beginnings
modern surgery took its rise, and the whole subject of wound infection,
not only in relation to surgical diseases, but to child-bed fever, forms
now one of the most brilliant chapters in the history of preventive
medicine.

(*) Lancet, March 16, 1867. (Cf. Camac: Epoch-making
Contributions, etc., 1909, p. 7.--Ed.)

With the new technique and experimental methods, the discovery of the
specific germs of many of the more important acute infections followed
each other with bewildering rapidity: typhoid fever, diphtheria,
cholera, tetanus, plague, pneumonia, gonorrhoea and, most important of
all, tuberculosis. It is not too much to say that the demonstration
by Koch of