niable that to the practice of vivisection we are
indebted for very much of our present knowledge of physiology. This is
the fortress of the advocates of vivisection, and a certain refuge
when other arguments are of no avail.

II. As a means of teaching physiological facts, vivisection is
unsurpassed. No teacher of science needs to be told the vast
superiority of demonstration over affirmation. Take for instance, the
circulation of the blood. The student who displays but a languid
interest in statements of fact, or even in the best delineations and
charts obtainable, will be thoroughly aroused by seeing the process
actually before his eyes. A week's study upon the book will less
certainly be retained in his memory than a single view of the opened
thorax of a frog or dog. There before him is the throbbing heart; he
sees its relations to adjoining structures, and marks, with a wonder
he never before knew, that mystery of life by which the heart, even
though excised from the body, does not cease for a time its rhythmic
beat. To imagine, then, that teachers of physiology find mere
amusement in these operations is the greatest of ignorant mistakes.
They deem it desirable that certain facts be accurately fixed in
memory, and they know that no system of mnemonics equals for such
purpose the demonstration of the function itself.

Just here, however, arises a very important question. Admitting the
benefit of the demonstration of scientific facts, _how far may one
justifiably subject an animal to pain for the purpose of illustrating
a point already known_? It is merely a question of cost. For instance,
it is an undisputed statement in physical science that the diamond is
nothing more than a form of crystallized carbon, and, like other forms
of carbon, under certain conditions, may be made to burn. Now most of
us are entirely willing to accept this, as we do the majority of
truths, upon the testimony of scientific men, without making
demonstration a requisite of assent. In a certain private school,
however, it has long been the custom once a year, to burn in oxygen a
small diamond, worth perhaps $30, so as actually to prove to the
pupils the assertion of their text-books. The experiment is a
brilliant one; no one can doubt its entire success. Nevertheless, we
do not furnish diamonds to our public schools for this purpose.
Exactly similar to this is one aspect of vivisection--it is a question
of cost. Granting all the advantages