f bacterial
growth--Death of bacteria--Immunity--Antitoxic sera--Identification
of bacteria--Pyogenic bacteria.

In the management of wounds and other surgical conditions it is
necessary to eliminate various extraneous influences which tend to delay
or arrest the natural process of repair.

Of these, one of the most important is undue movement of the affected
part. "The first and great requisite for the restoration of injured
parts is _rest_," said John Hunter; and physiological and mechanical
rest as the chief of natural therapeutic agents was the theme of John
Hilton's classical work--_Rest and Pain_. In this connection it must be
understood that "rest" implies more than the mere state of physical
repose: all physiological as well as mechanical function must be
prevented as far as is possible. For instance, the constituent bones of
a joint affected with tuberculosis must be controlled by splints or
other appliances so that no movement can take place between them, and
the limb may not be used for any purpose; physiological rest may be
secured to an inflamed colon by making an artificial anus in the caecum;
the activity of a diseased kidney may be diminished by regulating the
quantity and quality of the fluids taken by the patient.

Another source of interference with repair in wounds is _irritation_,
either by mechanical agents such as rough, unsuitable dressings,
bandages, or ill-fitting splints; or by chemical agents in the form of
strong lotions or other applications.

An _unhealthy or devitalised condition of the patient's tissues_ also
hinders the reparative process. Bruised or lacerated skin heals less
kindly than skin cut with a smooth, sharp instrument; and persistent
venous congestion of a part, such as occurs, for example, in the leg
when the veins are varicose, by preventing the access of healthy blood,
tends to delay the healing of open wounds. The existence of grave
constitutional disease, such as Bright's disease, diabetes, syphilis,
scurvy, or alcoholism, also impedes healing.

Infection by disease-producing micro-organisms or _pathogenic bacteria_
is, however, the most potent factor in disturbing the natural process of
repair in wounds.

SURGICAL BACTERIOLOGY

The influence of micro-organisms in the causation of disease, and the
role played by them in interfering with the natural process of repair,
are so important that the science of applied bacteriology has now come
to dominate ever