nteresting matter. The purpose of the author's
elaborate comparative study is to decide which has the strongest claims
to be regarded as the 'standard' method. They appear to have a
preference for the method of Lange--viz. that of heating at high
temperatures (180 deg.) with alkaline hydrates, but the investigation shows
that (as we had definitely stated in our original work, p. 214) this is
subject to large and variable errors. The adverse judgment of the
authors, we may point out, is entirely determined on the question of
aggregate weight or yield, and without reference to the ultimate
composition or constitution of the final product. None of the available
criteria are applied to the product to determine whether it is a
cellulose (anhydride) or a hydrate or a hydrolysed product. After these
alkali-fusion processes the method of chlorination is experimentally
reviewed and dismissed for the reason that the product retains
furfural-yielding groups, which is, from our point of view, a particular
recommendation, i.e. is evidence of the selective action of the chlorine
and subsequent hydrolysis upon the lignone group. As a matter of fact it
is the only method yet available for isolating the cellulose from a
lignocellulose by a treatment which is quantitatively to be accounted
for in every detail of the reactions. It does not yield a 'normal'
cellulose, and this is the expression which, in our opinion, the authors
should have used. It should have been pointed out, moreover, that, as
the cellulose is separated from actual condensed combination with the
lignone groups, it may be expected to be obtained in a hydrated form,
and also not as a homogeneous substance like the normal cotton
cellulose. The product is a cellulose of the second group of the
classification. Another point in this investigation which we must
criticise is the ultimate selection of the Schulze method of prolonged
maceration with nitric acid and a chlorate, followed by suitable
hydrolysis of the non-cellulose derivatives to soluble products. Apart
from its exceptional inconvenience, rendering it quite impracticable in
laboratories which are concerned with the valuation of cellulosic raw
materials for industrial purposes, the attack of the reagent is complex
and ill-defined. This criticism we would make general by pointing out
that such processes quite ignore the specific characteristics of the
non-cellulose components of the compound celluloses. The second divi