Page 112 - My FlipBook

that the chemist must assist the bacteriologist ; in fact, the
chemist, in the isolation and study of the special characters
of these products, is now doing the principal work in bac-
teriology.
Patholog^ical Effects of Enzymes.

There are a number of cases in which the enzyme of
growing micro-organisms seems to be the principal factor in
the production of disease, though not the only one, per-
haps, in any case. If the surface of the skin is pricked with
an infected instrument and an irritation is produced at the
same time that causes a little inflammatory movement, we
first have thrown out there a little bit of exudate that is co-
agulable ; the blood vessels in the neighborhood become en-
larged and engorged, and finally a cessation of the move-
ment occurs, the blood vessels become occluded with white
blood globules, and these pass out of the vessels also with
the coagulable exudate. Now, if this is not excessive it is
simply a process of repair normally taking place. Some sur-
geons would not regard it as an inflammation. The lips of
the wound, if it is a cut, will only be very slightly reddened,
nothing more, and this process is necessary to the healing
process, for these leucocytes that are thrown out in this
position are cells intended to develop and repair the break,
and thus far the process is a physiological inflammation, but
in its microscopic character there is no difference whatever
between this and the pathological inflammation. They are
both inflammations, but in the one case we have the condition
developing far enough simply to perform the repair. Now, if
in this needle prick or cut we have an infection of the micro-
organisms that I have passed to you this morning that have
melted down the gelatin, they begin to grow in that gelatin-
ous material that is thrown out about the injury, sustains
these leucocytes, and glues the lips of that wound together.
Their digestive product liquefies that coagulable exudate just
as it liquefies this gelatin in our tubes, and in that melting
down the material thrown out here (illustrating) for the re-
pair of the break is destroyed ; the coagulable exudate be-
comes fluid and carries with it the leucocytes that have been
thrown out in order to repair the wound. This is pus forma-
tion. You may prick a broach through the end of the root
of a tooth, and tear up the tissues in the apical space and

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