CHEMISTRY
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expired air, laden with the products of respiration, is withdrawn for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."
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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.