The record-union., 1894-05-01
HOW NATURE PROTECTS HUMANITY.
Different Kinds Of Diseases and Their
Classification.
Lecture Delivered by DR.. DARCY
Power. Last Night Before
the Unity Club.

DR.. D'Arcy Power of this city Oh how
Nature Protects Us From Disease"
In opening the lecture the speaker
stated that disease might be classlled ac-
cording to its causation: First, injuries
of the texture of the body, such as
wounds, burns. etc.; secondly, diseases
due to changes of temperature and eli
mate; thirdly, diseases due to changes in
the tissues of the body; and lastly, what
are known as infectious and contagious
diseases. Against all of these sources OF
i'll nature has provided protection
and remedies; the wonder and efficacy
of her methods makes the subject OF
moro than purely medical concern and
presents problems that are not only OF the
greatest public interest but also Of trans
cendent public value.
The first three groups of diseases were
but briefly dealt with. 1t was shown
that against gross injuries nature has pro-
vided three efficient protections-pain
without which we should never appreci-
ale the danger of injuries until too late;
instinct, which, not so greatly developed
in man as in the lower animals, Is still
present in childhood before the reason
can take It's place; and which in the ln-
stinctive closing of the eyelids against
blow or sudden light Is prominent
factor; and, lastly. the protection afforded
TO vital organs by their position, such as
the orbital ridge over the eye, the posi-
ton of the heart, brain. etc.
The second class, those due to changes
oftemperature, were shown to be guarded
against by a wonderful system of heat
regulation, automatically controlling the
amounts of blood supplied to the skin in
accordance with the surrounding tenn
perature.
OF the third class, it was pointed out
that when nature failed to save tissue or
organ from destruction she attempted to
repair tho damage done to the system by
increasing the activity of organs with a
like function; If one kidney were de-
sLroyed the other grew larger; if the lungs
failed the skin became more active and
relieved it OF some OF its work.
The main portion of the lecture was de-
voted TO a consideration of the fourth
class. DR.. Power pointed out that
great mystery had always surrounded
the infectious diseases that had only been
cleared up within very recent period.
All manner of explanations of their cause
had been offered, commencing with the
usual primitive conception of a visitation
OF God. Filth and dirt had the credit of
it for long time, not altogether without
reason, though it did not explain why
typhoid fever should always give rise to
typhoid fever and not to the cholera or
the plague, or some other malady equally
supposed to have its origin in dirt.
Finally, the search for the origin of life
by the believers in spontaneous gener-
alton, and the researches of their oppo-
nents, led to the discovery OF the true
cause. 1t was proved that infectious dis
eases were due TO the action of different
low and minute forms of life, either ami
NAL or vegetable, or on the borderland of
the two kingdoms. These reproduced
themselves in the body, and the disease
was the result of their activity. These
germs are often present i'll enormous
numbers; at some time or other every
one has been exposed to their attacks,
and yet many never succumb to their in
fiuences.
How has nature protected these fortu-
nate individuals? Here was difficult
problem, but it has been solved. 1t was
known that the blood contained numer-
Gus particles called white blood corpus
cles, which were mobile and alive: and re-
sembled the little fresh water animals,
called am0ba, in their structure and
movements. 1t was known that they
were in the habit OF absorbing into
themselves literally eating up any for
eign particles that gained access to the
body; it was known that they could eat
up. when necessary, part of the body
itself. That IN this way the tail of the
tadpole was removed when the change of
that animal into a frog rendered it no
longer useful. All these things were
known when Metschinilod observed that
when certain little water bea, called
toaphuia. eat certain fungus (allied to
the bacteria that produces disease in
mani, the spores of the fungus made their
way through its stomach into the body. and
there they were seized on by the white
blood corpuscles OF the water flea. which
took them into their substance and di-
gested them; but that sometimes the
white blood corpuscles did not digest
them, but died instead; and the fungus
lived, reproduced itself, and finally killed
the animal into which it had gained adj
mission.
Here was the clue to the phenomena of
infection in man. Observation showed
that, in disease, the white blood cor
puScles also eat the microbes that are
present in such conditions, and so we
have come to believe that when these
dangerous little organisms effect an en-
trance into our body, they have to fight
for possession with the white blood cor
puscles that oppose them, and the victory
is to the stronger or the more numerous,
and so 1t is that some people never con-
tract infectious diseases-their white
blood corpuscles are too active And.
again, as the activity of these little war
riors is dependent on the general health,
so II is that during debility the body is
more likely TO be successfully attacked.
The last problem solved is, how it is
that having one attack of an infectious
disease gives more or less immunity
against future attacks, and again modern
investigation has given solution. First,
IL was known that these lowly organisms
produced or execreted different chemical
substances of more or less poisonous
nature; the yeast plant alcohol; another
fungus, vinegar; others again the gases
OF pGtreiaetion. Then it was demon
strated that the symptoms of many in
1ectlouS diseases were produced not di-
rectly by the germs themselves, but by
the chemical products they produced.
Finally, 1t was well known that the
body readily acquires tolerance for any
substance 1t has frequently and slowly
imbibed. In this way we learn to smoke:
some persons are able TO take quantities
of alcohol, morphia, and other poisons
that would be immediately fatal to the
unhaDituated; from all of which con-
sideration 1t is now abundantly clear that
our so-called immunity Isl obtained in the
same way. We do not get second at
tack of smallpox. or scarlet fever, be-
cause the body Is habituated to the
poison by the first attack, and when re-
introduced the poison generated by the
germs is unable 10 affect the W white blood
corpuscles, that soon eat up and destroy
the invaders.
But, as some people never get used TO
tobacco, or alcohol, so some never get
habituated to the poison OF scarlatina.
etc. They therefore get an attack when
ever they are subjected to it's influence.
In conclusion, the lecture dwelt on the
immense public importance of these in
vestigations. It needed bat the CO.
operation of the laity to abolish infectious
diseases, including that worst of all
scourges, consumption. iii the near future.
AS dangerous wild animals have been