olecule C_{12}H_{18}O_{9} (= 306) is therefore 462,
whereas for a tetranitrate formed by a simple ester reaction the yield
should be 486. The difference (24) represents 1.5 mol. H_{2}O split off
by internal condensation.

The correction for total N is relatively small, raising it from 11.5 to
12.2, which remains in close agreement with the experimental numbers.

_Monobenzoate._--Treated with the acid mixture yields a mixed nitrate.
The yield is 130 p.ct., and the product contains 7.6 p.ct. O.NO_{2}
nitrogen. These numbers approximate to those required for reaction with
4HNO_{3} groups, three of the residues entering the cellulose, and one
(as NO_{2}) the benzene ring of the substituting group. For such a
reaction the calculated numbers are: Yield 144 p.ct.; O.NO_{2} nitrogen
7.1 p.ct.

The experimental numbers require correcting for the amount of loss in
the form of products soluble in the acid mixture, viz. 7.6 p.ct.; but
they remain within the range of the experimental errors sufficiently to
show that the benzoyl group limits the number of OH groups taking part
in the ester reaction to three. The corrected yield per 1 mol. of jute
benzoate (410) is 576, as against the calculated 590 for 4HNO_{3}
reacting. A loss of 1H_{2}O per molecule by internal condensation is
therefore indicated.

~Denitration.~--The removal of the nitric groups from the esters is
effected by digestion with ammonium sulphide. But the reactions are by
no means simple. There is considerable hydrolysis of the lignocellulose
to soluble products. Thus the _tetranitrate_ yields only 46.4 of
denitrated fibre in place of the calculated 66. The product is a
cellulose, yielding only 0.5 per cent. furfural. The hydrolysed
by-products, moreover, when freed from sulphur and distilled from
hydrochloric acid, yielded only an additional 2.5 p.ct. furfural,
calculated to the original lignocellulose.

These statistics confirm the evidence that the ester reaction is not
simple. Such changes take place in the lignone-beta-cellulose complex
that they revert, not to their original form, but to soluble derivatives
of different constitution. The mixed nitrate from the benzoate is
denitrated to a cellulose amidobenzoate, which confirms the localisation
of a nitro-group in the benzoyl residue.

(p. 157) ~General Characteristics of the Lignocelluloses.~--Later
investigations have somewhat modified and simplified our views of the
constitution of the typical lignocellu