of the other pus-causing micro-organisms.

How much more intelligent is this explanation than the old one that
diffuse abscesses depended upon some curious characteristic of the
patient. It is a satisfaction to know that the two forms of abscess
differ because they are the result of inoculation with different
germs. It is practically a fact that wherever there is found a diffuse
abscess there will be discovered the streptococcus pyogenes, which is
the name of the chain coccus above mentioned.

So, also, is it easy now to understand the formation of what the old
surgeons called "cold" abscesses, and to account for the difference in
appearance of its puriform secretion from the pus of acute abscesses.
Careful search in the fluid coming from such "cold" abscesses reveals
the presence of the bacillus of tuberculosis, and proves that a "cold"
abscess is not a true abscess, but a lesion of local tuberculosis.

Easy is it now to understand the similarity between the "cold abscess"
of the cervical region and the "cold abscess" of the lung in a
phthisical patient. Both of them are, in fact, simply the result of
invasion of the tissues with the ubiquitous tubercle bacillus; and are
not due to pus-forming bacteria.

Formerly it was common to speak of the scrofulous diathesis, and
attempts were made to describe the characteristic appearance of the
skin and hair pertaining to persons supposed to be of scrofulous
tendencies. The attempt was unsuccessful and unsatisfactory. The
reason is now clear, because it is known that the brunette or the
blond, the old or the young, may become infected with the tubercle
bacillus. Since the condition depends upon whether one or the other
become infected with the generally present bacillus of tubercle, it is
evident that there can be no distinctive diathesis. It is more than
probable, moreover, that the cutaneous disease so long described as
lupus vulgaris is simply a tubercular ulcer of the skin, and not a
special disease of unknown causation.

The metastatic abscesses of pyaemia are clearly explained when the
surgeon remembers that they are simply due to a softened blood clot
containing pus-causing germs being carried through the circulation and
lodged in some of the small capillaries.

A patient suffering with numerous boils upon his skin has often been a
puzzle to his physician, who has in vain attempted to find some cause
for the trouble in the general health alone. Had he known that eve