of hydrolytic treatments, acid
and alkaline, in order to determine the conditions of selective action
upon the mother substance of the wood-gum. In the main it appears that
this group of furfuroids is equally resistant with the cellulose
constituents of the wood; in fact, that the mother substance of wood-gum
is a modified cellulose, and exists in the wood in chemical combination
with the 'incrusting substances.'

Of the author's experimental results the following may be cited as
typical:

Yield of furfural
Substance p.ct.
Original beech-wood 13.8

After boiling 3 hrs. with 1.25 p.ct. H_{2}SO_{4} (residue) 10.1

" " " " 5.0 " " " 5.6

Cellulose--isolated by Schulze process (yield 53 p.ct.) 6.9

" after further 14 days' digestion with the
Schulze acid (HNO_{3} + KClO_{3}) 5.9

" after extraction with 5 p.ct. NaOH in
cold (residue) 5.0

" after second extraction with 5 p.ct. NaOH
in cold (residue) 4.4

UEBER DIE FRAGE NACH DEM URSPRUNG UNGESAeTTIGER VERBINDUNGEN IN DER
PFLANZE.

C. F. CROSS, E. J. BEVAN, and C. SMITH (Berl. Ber., 1895, 1940).

~ON THE SOURCE OF THE UNSATURATED COMPOUNDS OF THE PLANT.~

(p. 179) In distilling for furfural by the usual methods of boiling
cellulosic products with condensing acids, the furfural is accompanied
by volatile acids, also products of decomposition of the cellulosic
complex. A series of distillations was carried out with dilute sulphuric
acids of varying concentration from 10-50 H_{2}SO_{4} : 90-50 H_{2}O by
weight, using barley straw as a typical cellulosic material. The
distillates were collected in successive fractions, and the furfural and
volatile acid determined. The results are given in the form of curves.
The aggregate yields were as follows:--

Concentration of acid
(H_{2}SO_{4}) p.ct. 10 15 20 30 40 50

Furfural yield p.ct. of straw 2.0 2.0 4.4 10.1 11.5 11.0

Volatile acid (calculated
as acetic acid) p.ct. of straw 1.7 1.9 3.1 4.3 6.3 14.8

With acids up to 20 p.ct. H_{2}SO_{4} both products are formed
concurrently and in nearly equal quantity. With the 30 p.ct. acid there