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


Intelligent vivisection--Its Results Add
to tho Certaintics of tho Medical Art.
How Harvey Worked.
The discussion at the church congress on
che 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, OF
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 Ineligible 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 the 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 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 n phrase and
nothing more. But the work of Harvey
bears about the same relation to the su bse-
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 al
Harvey's disposal for this special purpose
| and came himself to witness the expert
ments as soon as the results were suf
ficiently declared ..4Ia,.f
The work which Harvey accomplished
for the Benefit of all future generations oi
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 second example o1
the kind OF experimentation which we have
placed in the first group we may pass from,
the oirculatory to the nervous system
which will furnish us with an instance al
least as remarkable and at least as stronl
as that which has been already dealt with
To take third example from the samt
group, DR.. Hopes experiments on living
animals cleared up much which had before
been doubtful regarding heart disease, not
withstandipg 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, o.
to Won Graefe's operations for the cure O
glaucoma. The results obtained by ex
periments on the legation of arteries, from
the time of Hunter onward, have led to {
very great and constantly increasing say
ing Of human life
The third group embraces very large
number of experiments, the details o.
which would mostly be unintelligible t,
nonmedical persons, but which have served
10 establish the action Of some medica
ment.
The fourth group includes the so called
"inoculation" and 'feeding'' experiments
which have been extensively performed il
connection with modern bacteriology, ant
the main features of which have becom,
widely known. 1t has been established BY
these that the active cause of many forml
of disease is a special microbe, and that il
some instances this microbe may be cult
waited or reared in such manner as t,
diminish the virulence of it's effects, 81
that it will confer when introduced int
the body of man or an animal, immunit,
from severe disease by the production O
a mild one. The effect Of incubation ex
periments has been to identity the severa
microbes Of many diseases, to prove tina
they are the causes Of these diseases, +,
test the degree in which their effects ma!
be diminished by cultivation, and tine de
gree In which these diminished effects vii
afford prOt action univ 81 fn0ru1ntior, ooci