petent critic, makes use of the short
expression in regard to the more complex carbohydrates, 'Above cane
sugar, higher in the series, all is chaos,' and in reference to starch,
'the subject is still enshrouded in mystery.' This 'material' complexity
is at its maximum with the most complex members of the series, which are
the celluloses, and we think accounts in part for the impatience of our
critic. 'Obscurity of diction' is a personal quantity, and we must leave
that criticism to the fates. We find also that many workers whose
publications we notice in this present volume quite ignore the _plan_ of
the work, though they make use of its matter. We think it necessary to
restate this plan, which, we are satisfied, is systematic, and, in fact,
inevitable. Cellulose is in the first instance a _structure_, and the
anatomical relationships supply a certain basis of classification. Next,
it is known to us and is defined by the negative characteristics of
resistance to hydrolytic actions and oxidations. These are dealt with in
the order of their intensity. Next we have the more positive definition
by ultimate products of hydrolysis, so far as they are known, which
discloses more particularly the presence of a greater or less proportion
of furfural-yielding groups. Putting all these together as criteria of
function and composition we find they supply common or general dividing
lines, within which groups of these products are contained. The
classification is natural, and in that sense inevitable; and it not only
groups the physiological and chemical facts, but the industrial also. We
do not propose to argue the question whether the latter adds any cogency
to a scientific scheme. We are satisfied that it does, and we do not
find any necessity to exclude a particular set of phenomena from
consideration, because they involve 'commercial' factors. We have dealt
with this classification in the original work (p. 78), and we discuss
its essential basis in the present volume (p. 28) in connection with the
definition of a 'normal' cellulose. But the 'normal' cellulose is not
the only cellulose, any more than a primary alcohol or an aliphatic
alcohol are the only alcohols. This point is confused or ignored in
several of the recent contributions of investigators. It will suffice to
cite one of these in illustration. On p. 16 we give an account of an
investigation of the several methods of estimating cellulose, which is
full of valuable and i