It is not making too strong a statement to say
that the chemistry and chemical physics of the nineteenth
century have revolutionized the world. It is
difficult to realize that Liebig’s famous Giessen
laboratory, the first to be opened to students for
practical study, was founded in the year 1825.
Boyle, Cavendish, Priestley, Lavoisier, Black, Dalton
and others had laid a broad foundation, and Young,
Frauenhofer, Rumford, Davy, Joule, Faraday, Clerk-Maxwell,
Helmholtz and others built upon that and gave us the
new physics and made possible our age of electricity.
New technique and new methods have given a powerful
stimulus to the study of the chemical changes that
take place in the body, which, only a few years ago,
were matters largely of speculation. “Now,”
in the words of Professor Lee, “we recognize
that, with its living and its non-living substances
inextricably intermingled, the body constitutes an
intensive chemical laboratory in which there is ever
occurring a vast congeries of chemical reactions; both
constructive and destructive processes go on; new
protoplasm takes the place of old. We can analyze
the income of the body and we can analyze its output,
and from these data we can learn much concerning the
body’s chemistry. A great improvement in
the method of such work has recently been secured
by the device of inclosing the person who is the subject
of the experiment in a respiration calorimeter.
This is an air-tight chamber, artificially supplied
with a constant stream of pure air, and from which
the expired air, laden with the products of respiration,
is withdrawn for purposes of analysis. The subject
may remain in the chamber for days, the composition
of all food and all excrete being determined, and
all heat that is given off being measured. Favorable
conditions are thus established for an exact study
of many problems of nutrition. The difficulties
increase when we attempt to trace the successive steps
in the corporeal pathway of molecule and atom.
Yet these secrets of the vital process are also gradually
being revealed. When we remember that it is in
this very field of nutrition that there exist great
popular ignorance and a special proneness to fad and
prejudice, we realize how practically helpful are
such exact studies of metabolism."(13)
(13) Frederick S.
Lee, Ph.D.:
Scientific Features of Modern Medicine, New York,
1911. I would like to call attention to this
work of Professor Lee’s as presenting all
the scientific features of modern medicine in
a way admirably adapted for anyone, lay or medical,
who wishes to get a clear sketch of them.
