at an
exposition of the subject "to date".

PREFACE

This volume, which is intended as a supplement to the work which we
published in 1895, gives a brief account of researches which have been
subsequently published, as well as of certain of our own investigations,
the results of which are now for the first time recorded.

We have not attempted to give the subject-matter the form of a connected
record. The contributions to the study of 'Cellulose' which are noticed
are spread over a large area, are mostly 'sectional' in their aim, and
the only cohesion which we can give them is that of classifying them
according to the plan of our original work. Their subject-matter is
reproduced in the form of a _precis_, as much condensed as possible; of
the more important papers the original title is given. In all cases we
have endeavoured to reproduce the Author's main conclusions, and in most
cases without comment or criticism.

Specialists will note that the basis of investigation is still in a
great measure empirical; and of this the most obvious criterion is the
confusion attaching to the use of the very word 'Cellulose.' This is due
to various causes, one of which is the curious specialisation of the
term in Germany as the equivalent of 'wood cellulose.' The restriction
of this general or group term has had an influence even in scientific
circles. Another influence preventing the recognition of the obvious
and, as we think, inevitable basis of classification of the 'celluloses'
is the empiricism of the methods of agricultural chemistry, which as
regards cellulose are so far chiefly concerned with its negative
characteristics and the analytical determination of the indigestible
residue of fodder plants. Physiologists, again, have their own views and
methods in dealing with cellulose, and have hitherto had but little
regard to the work of the chemist in differentiating and classifying the
celluloses on a systematic basis. There are many sides to the subject,
and it is only by a sustained effort towards centralisation that the
general recognition of a systematic basis can be secured.

We may, we hope usefully, direct attention to the conspicuous neglect of
the subject in this country. To the matter of the present volume,
excluding our own investigations, there are but two contributions from
English laboratories. We invite the younger generation of students of
chemistry to measure the probability of finding a working ca