The presentation of essential data concerning vitamines to succeeding
groups of students has become increasingly difficult with the development
of research in this field. The literature itself has assumed a bulk that
precludes sending the student to original sources except in those
instances when they are themselves to become investigators. The demand on
the part of the layman for concise information about the new food factors
is increasing and worthy of attention. For all of these reasons it has
seemed worth while to collate the existing data and put it in a form which
would be available for both student and layman. Such is the purpose of
this little book.

It has been called a manual since the arrangement aims to provide the
student with working material and suggestions for investigation as well as
information. The bibliography, the data in the chapter on vitamine
testing, the tables and the subdivision of subject matter have all been
arranged to aid the laboratory workers and it is the hope that this plan
may make the manual of especial value to the student investigator. The
management also separates the details necessary to laboratory
investigation from the more purely historical aspects of the subject which
we believe will be appreciated by the lay reader as well as the student.

No apologies are made for data which on publication shall be found
obsolete. The whole subject is in too active a state of investigation to
permit of more than a record of events and their apparent bearing.
Whenever there is controversy the aim has been to cite opposing views and
indicate their apparent value but with full realization that this value
may be profoundly altered by new data.

Since the type of the present manual was set, Drummond of England has