In the present edition of this work a few new subjects have been added
and the text has been somewhat altered in order that certain recent
advances and changes might be noted and brought into daily service.
I have not been unmindful, however, of the fact that to be of the
greatest possible use to our profession this volume must remain small
and compact.
I hear frequently that this Handbook is valued by my fellow-workers and
that it is to many of them a daily help and companion. This is a source
of great pleasure to me, and I hope that this new edition will be found
more useful even than any of its predecessors.
A. K. BECK, R. N.
CHICAGO, ILL.,
_March, 1919_.