ations a number of observations have been
made on the alkali-cellulose (cotton) after prolonged storage in closed
vessels. It is well known that starch undergoes hydrolysis in contact
with aqueous alkalis of a similar character to that determined by acids
[Bechamp, Annalen, 100, 365]. The recent researches of Lobry de Bruyn
[Rec. Trav. Chim. 14, 156] upon the action of alkaline hydrates in
aqueous solution on the hexoses have established the important fact of
the resulting mobility of the CO group, and the interchangeable
relationships of typical aldoses and ketoses. It was, therefore, not
improbable that profound hydrolytic changes should occur in the
cellulose molecule when kept for prolonged periods as alkali-cellulose.

We may cite an extreme case. A series of products were examined after
12-18 months' storage. They were found to contain only 3-5 p.ct.
'soluble carbohydrates'; these were precipitated by Fehling's solution
but without reduction on boiling. They were, therefore, of the cellulose
type. On acidifying with sulphuric acid and distilling, traces only of
volatile acid were produced. It is clear, therefore, that the change of
molecular weight of the cellulose, the disaggregation of the undoubtedly
large molecule of the original 'normal' cellulose--which effects are
immediately recognised in the viscose reactions of such products--are of
such otherwise limited character that they do not affect the
constitution of the unit groups. We should also conclude that the
cellulose type of constitution covers a very wide range of minor
variations of molecular weight or aggregation.

The resistance of the normal cellulose to the action of alkalis under
these hydrolysing conditions should be mentioned in conjunction with the
observations of Lange, and the results of the later investigations of
Tollens, on its resistance to 'fusion' with alkaline hydrates at high
temperatures (180 deg.). The degree of resistance has been established only
on the empirical basis of weighing the product recovered from such
treatment. The product must be investigated by conversion into typical
cellulose derivatives before we can pronounce upon the constitutional
changes which certainly occur in the process. But for the purpose of
this discussion it is sufficient to emphasise the extraordinary
resistance of the normal cellulose to the action of alkalis, and to
another of the more significant points of differentiation from starch.

_Chemical