The herald., 1893-02-19
TESTS ON ANIMALS.
THE KNOWLEDGE THEY YIELD IN
PHYSIOLOGY.

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The discussion at the church congress on
the subject of Experiments Upon Living
Animals" and the correspondence which
followed it have naturally led to some re-
newal of interest in the whole of the ques-
tions involved, and especially in one OF
them, on which, in the opinion of most
people, the decision concerning others
should depend. We refer to the question
of the actual benefit to the human race, or
even to the lower animals themselves,
which these experiments have been the
means Of comforting, and we propose to set
forth some of these benefits in manner
calculated to be intelligible to nonmedical
readers.
The words Experimentation on living
animals" cover very wide range of proce-
dure, and it may therefore be desirable, in
the first place, to attempt to classify expert
mental work with reference to its nature
and objects. Experiments are performed;
AS an orderly series, intended to ascer-
tain the functions of organs or assemblages
of organs in she human or animal body.
As detached proceedings, intended to de-
eide some single questions which may arise
during the course of an illness or in the
progress of a medico-legal investigation,
such question, for example, as the prac-
ticability and applicability Of proposed
operation or the nature of poison which
defies chemical analysis.
Either singly or in series, for the purpose
of ascertaining the initial and ultimate
action of some drug upon the human Or
ganism, with the view either of testing its
value as a remedial agent or of guarding,
by antidote or otherwise, against its inju-
rious effects.
incubation and feeding experiments, in
tended to identify the specific microhe Of
some disease and to ascertain whether,
and if so, in what degree, its virulence is
capable of being destroyed or mitigated by
cultivation or other circumstances.
Besides the experiments which fall under
one or other of the foregoing groups there
may be others which it would be difficult
to classify, but the groups will serve to in
clude the greater number, and each will
furnish illustrations of valuable results
which could probably have been attained
in no other manner.
AS conspicuous example of the first
group we may recall to mind the expert
ments Of DR.. William Harvey by which he
discovered the circulation Of the blood.
There may be thousands of educated peo-
pie to whom this phrase is a phrase and
nothing more. But the work Of Harvey
bears about the same relation to the subse-
quent progress of medicine as that of Gal
Ill to the subsequent progress of astron-
omy.
To the physician of the present day the
ignorance of animal function which pre-
vailed before Harvey, and which his dis
coveries served in time to dispel, can
scarcely be realized by any effort of the
imagination, and it would be impossible
to conceive of any progress in physiology
or of any progress in medicine which could
have been made prior to the completion OF
his work. Every portion Of that work,
from it's commencement to its close, was
accomplished and established by expert
ments upon living animals, and could have
been accomplished in no other way. The
king placed the deer of the royal parks at
Harvey's disposal for this special purpose
and came himself to witness the expert
ments as soon as tho results were suf'
hciently declared. t.g.t
The work which Harvey accomplished
for the Benefit of all future generations Of
the human race has been SO fruitful that
it is scarcely possible to point to any subse.
quent discovery in physiology or in medi-
cine which has not more or less directly
followed from it,
In order to discover O second example OF
the kind OF experimentation which we have
placed in the first group we may pass from
the circulatory to the nervous system,
which will furnish us with an instance at
least as remarkable and at least as strong
as that which has been already dealt WITH
To take a third example from the same
group, DR.. Hopes experiments on living
animals cleared up much which had before
been doubtful regarding heart disease, not
withstanding bedside experience and post
mortem examinations, and have enabled
physicians ever since to detect the earliest
indications of cardiac changes and correct
ly to appreciate the sounds which are sig
nificant of improvement or of deterioration.
Proceeding to the second group, an ex-
cellent example of them is furnished by
the experiments preliminary to John Hun
ter's operations for the cure of aneurism, or
to Won Graefe's operations for the cure of
glaucoma. The results obtained by ex-
periments on the legation of arteries, from
the time of Hunter onward, have led to a
very great and constantly increasing saw
ing Of human life.
The third group embraces very large
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which would mostly be unintelligible to
nonmedical persons, but which have served
20 establish the action Of some medica
ment.
The fourth group includes the SO called
"inoculation" and feeding" experiments,
which have been extensively performed in
connection with modern bacteriology, and
the main features of which have become
widely known. 1t has been established by
these that the active cause of many forms
of disease is a special microbe, and that in
some instances this microbe may be culti-
waited or reared in such q manner as to
diminish the virulence of it's effects, so
that it will confer, when introduced into
the body of a man or an animal, immunity
from severe disease by the production of
a mild one. The effect of incubation ex-
periments has been to identify the several
microbes Of many diseases, to prove that
they are the causes OF these diseases, to
test the degree in which their effects may
be diminished by cultivation, and tine de-
gree In which these diminished effects will
afford protection against fnoculation, acci-
dental or designed. with the more ordinary
forms. s.-London Times.