JAN. 4, 1923 PROCEEDINGS: WASHINGTON ACADEMY OF SCIENCES 15 
linus; epidemiology of botulism. The detailed results of the investigation 
are given in a series of articles that are appearing in the Journal of Infectious 
Diseases. 
170TH MEETING 
The 170th meeting of the AcapEmy was held jointly with the Biological 
Society of Washington and the Chemical Society of Washington in the 
Assembly Hall of the Cosmos Club, the evening of Thursday, October 19, 
1922. Dr. H. J. Hamsurcer, Professor of Physiology, University of Gron- 
ingen, Holland, delivered an address, entitled, The increasing significance of 
chemistry in medical thought and practice. 
Doctor HamBuRGER reviewed briefly the contributions of the older schools 
of thought to the chemical aspects of medicine, dwelling particularly upon 
the experiments of Paracelsus. In these early contributions there can be 
seen the first faltering steps in the construction of a mechanistic physiology. 
With the advent of modern chemical experimentation many of the bodily 
processes which had been regarded as under ‘‘vitalistic’”? control were shown 
to be under the control of such clearly defined forces as those of osmosis, 
electrolytic dissociation, and specific chemical reactions. 
The complexity of the problem faced by the chemist is illustrated by the 
proteins. The chemist has isolated and identified the amino-acids of which 
the proteins are composed and he has shown how these, like bricks, may be 
put together to form an infinite variety in protein architecture. He has 
actually synthesized proteins of immense molecular weight, and although 
he can not fomulate the detailed structures of the infinite variety of proteins 
found in nature he can account for the variety demonstrated by the delicate 
reactions of immunology. | 
Of late it has been shown that the body forms substances which, circulating 
in the blood, act as messengers to control various processes. Two of these 
have been identified chemically and many more are known by their physio- 
logical action. The presence or absence of one or another of these so-called 
hormones may determine a specific set of characteristics. For instance, it 
has been experimentally demonstrated that the sex of a young animal may 
be altered by the removal of the ovaries and the implantation of testes. 
As each contribution of chemistry is applied in medicine the case for the 
mechanistic physiology becomes stronger. 
Wiuuiam R. Maxon, Recording Secretary. 
