Page 129 - My FlipBook
P. 129
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to diseases that affect other animals. The hog is immune to
snake poison—the natural enemy of the snake—the bite of a
rattlesnake is of no consequence to the hog. Now we may
become immune to snake bites, or to certain diseases by un-
dergoing certain processes. In most of them it is having the
disease. We may become practically immune to poisoning
by arsenic we may become in large degree immune to the
;
poisoning with morphia. Now, the chemist has been follow-
ing these conditions of immunity and susceptibility by ex-
aminations of the blood in the endeavor to find out what
material thing there is in the blood that may prevent the oc-
currence of this poisoning—for it is the prevention of poison-
ing that brings about this immunity—and two classes of
substances have been found. These are called defensive
protcids. This was the first term applied to substances found
in the blood that prevented poisoning, or prevented the
growth of micro-organisms in the blood. Later these have
been divided into two groups—the alexins and the antitox-
ins. The alexins are substances that act as antiseptics, or
substances that prevent the growth of micro-organisms.
The amount of alexin in the blood of an animal determines
the condition of susceptibility or immunity. If alexin is
found in the blood in a large amount that animal will be
generally immune to bacterial disease ; if it is small in amount
the animal will be generally susceptible. I am speaking now
of classes of animals. If in the particular animal the amount
of alexin is large, that particular animal will be refractory, as
bacteriologists say, to microbic diseases ; it will be difficult to
get a culture of micro-organisms to grow in the tissues of
that animal. If the amount of alexin is small it will be com-
paratively easy to get micro-organisms to grow in the tis-
sues of the animal, and so on.
The other substances antitoxins—are of a different na-
ture. They are direct antidotes to the particular poison.
And these are developed in the blood apparently by reason
of contact with the particular poison which they antidote.
I want you to get the meaning of this, and perhaps there
is nothing that will appeal to you more closely just now than
these sore arms from vaccination, and I may be excused,
perhaps, for saying something more than I would usually say
with reference to the vaccine virus. The man becomes in-
117
to diseases that affect other animals. The hog is immune to
snake poison—the natural enemy of the snake—the bite of a
rattlesnake is of no consequence to the hog. Now we may
become immune to snake bites, or to certain diseases by un-
dergoing certain processes. In most of them it is having the
disease. We may become practically immune to poisoning
by arsenic we may become in large degree immune to the
;
poisoning with morphia. Now, the chemist has been follow-
ing these conditions of immunity and susceptibility by ex-
aminations of the blood in the endeavor to find out what
material thing there is in the blood that may prevent the oc-
currence of this poisoning—for it is the prevention of poison-
ing that brings about this immunity—and two classes of
substances have been found. These are called defensive
protcids. This was the first term applied to substances found
in the blood that prevented poisoning, or prevented the
growth of micro-organisms in the blood. Later these have
been divided into two groups—the alexins and the antitox-
ins. The alexins are substances that act as antiseptics, or
substances that prevent the growth of micro-organisms.
The amount of alexin in the blood of an animal determines
the condition of susceptibility or immunity. If alexin is
found in the blood in a large amount that animal will be
generally immune to bacterial disease ; if it is small in amount
the animal will be generally susceptible. I am speaking now
of classes of animals. If in the particular animal the amount
of alexin is large, that particular animal will be refractory, as
bacteriologists say, to microbic diseases ; it will be difficult to
get a culture of micro-organisms to grow in the tissues of
that animal. If the amount of alexin is small it will be com-
paratively easy to get micro-organisms to grow in the tis-
sues of the animal, and so on.
The other substances antitoxins—are of a different na-
ture. They are direct antidotes to the particular poison.
And these are developed in the blood apparently by reason
of contact with the particular poison which they antidote.
I want you to get the meaning of this, and perhaps there
is nothing that will appeal to you more closely just now than
these sore arms from vaccination, and I may be excused,
perhaps, for saying something more than I would usually say
with reference to the vaccine virus. The man becomes in-
117
