ng only
cotton and linen celluloses, was further purified by boiling with dilute
acid and dilute alkali. After thorough washing it was air-dried.

(b) _Wood cellulose._--Pine wood sawdust was treated by digestion for
fourteen days with dilute nitric acid with addition of chlorate
(Schulze). The mass was washed and digested with alkaline lye (1.25
p.ct. KOH), and exhaustively washed, treated with dilute acetic acid;
again washed, and finally air-dried.

This product was found to yield 2.3 p.ct. furfural on distillation with
HCl (1.06 sp.gr.).

(c) _Purified wood._--Pine wood sawdust was treated in succession with
dilute alkalis and acids, in the cold, and with alcohol and ether until
exhausted of products soluble in these liquids and reagents.

In addition to the above the authors have also employed jute fibre and
raw cotton wool in their investigations.

They note that the yield of cellulose is in many cases sensibly lowered
by treating the material after drying at the temperature of 100 deg.. The
material for treatment is therefore weighed in the air-dry condition,
and a similar sample weighed off for drying at 100 deg. for determination of
moisture.

The main results of the experimental investigation are as follows:--

_Weende process_ further attacks the purified celluloses as follows:
Wood cellulose losing in weight 8-9 p.ct.; filter paper, 6-7.5 p.ct.,
and the latter treated a second time loses a further 4-5 p.ct. It is
clear, therefore, that the process is of purely empirical value.

_Schulze._--This process gave a yield of 47.6 p.ct. cellulose from pine
wood. The celluloses themselves, treated by the process, showed losses
of 1-3 p.ct. in weight, much less therefore than in the preceding case.

_Hoenig's_ method of heating with glycerin to 210 deg. was found to yield
products very far removed from 'cellulose.' The process may have a
certain value in estimations of 'crude fibre,' but is dismissed from
further consideration in relation to cellulose.

_Lange._--The purpose of the investigation was to test the validity of
the statement that the celluloses are not attacked by alkaline hydrates
at 180 deg.. Experiments with pine wood yielded a series of percentages for
cellulose varying from 36 to 41; the 'purified wood' gave also variable
numbers, 44 to 49 per cent. It was found possible to limit these
variations by altering the conditions in the later stages of isolating
the product; but further experiment