d to
Blaisdell's _How to Teach Physiology_, a handbook for teachers. A copy
of this pamphlet will be sent postpaid to any address by the
publishers of this book on receipt of ten cents.]

The experimental method of instruction rivets the attention and arouses
and keeps alive the interest of the young student; in fact, it is the
only true method of cultivating a scientific habit of study[57]. The
subject-matter as set forth on the printed pages of this book should be
mastered, of course, but at the same time the topics discussed should be
illuminated and made more interesting and practical by a well-arranged
series of experiments, a goodly show of specimens, and a certain amount of
microscopical work.

408. The Question of Apparatus. The author well understands from
personal experience the many practical difficulties in the way of
providing a suitable amount of apparatus for classroom use. If there are
ample funds for this purpose, there need be no excuse or delay in
providing all that is necessary from dealers in apparatus in the larger
towns, from the drug store, markets, and elsewhere. In schools where both
the funds and the time for such purposes are limited, the zeal and
ingenuity of teachers and students are often put to a severe test.
Fortunately a very little money and a great deal of ingenuity and patience
will do apparent wonders towards providing a working supply of apparatus.

It will be noticed that many of the experiments in the preceding chapters
of this book can be performed with very simple, and often a crude and
home-made sort of apparatus. This plan has been rigidly followed by the
author, first, because he fully realizes the limitations and restrictions
of the subject; and secondly, because he wishes to emphasize the fact that
expensive and complicated apparatus is by no means necessary to illustrate
the great principles of anatomy and physiology.

409. Use of the Microscope. To do thorough and satisfactory work in
physiology in our higher schools a compound microscope is almost
indispensable. Inasmuch as many of our best secondary schools are equipped
with one or more microscopes for use in other studies, notably botany, it
is much less difficult than it was a few years ago to obtain this
important help for the classes in physiology.

[Illustration: Fig. 170.--A Compound Microscope]

For elementary class work a moderate-priced, but well-made and strong,
instrument should be provid