mely
unstable, showing a loss of weight of 30-40 p.ct. when kept 24 hours at
this temperature.

Xylose is differentiated by tending to pass into an anhydride form
(C_{5}H_{10}O_{5}-H_{2}O) under this esterification. When treated in
fact with the mixed acids, instead of by the process usually adopted by
the authors of solution in nitric acid and subsequent addition of the
sulphuric acid, it is converted into the dinitrate
C_{5}H_{6}O_{2}.(NO_{3})_{2}.

_Ketoses_ (C_{6}).--These are sharply differentiated from the corresponding
aldoses by giving _tri_nitrates C_{6}H_{7}O_{2}(NO_{3})_{3} instead
of _penta_nitrates, the remaining OH groups probably undergoing internal
condensation. The products are, moreover, _extremely stable_. It is also
noteworthy that levulose gave this same product, the trinitrate of the
anhydride (levulosan) by both methods of nitration (_supra_).

_The bisaccharides or bioses_ all give the octonitrates. The degree of
instability is variable. Cane-sugar gives a very unstable nitrate. The
lactose nitrate is more stable. Thus at 50 deg. it loses only 0.7 p.ct. in
weight in eight days; at 75 deg. it loses 1 p.ct. in twenty-four hours, but
with a rapid increase to 23 p.ct. in fifty-four hours. The maltose
octonitrate melts (with decomposition) at a relatively high temperature,
163 deg.-164 deg.. At 50 deg.-75 deg. it behaves much like the lactose nitrate.

_Trisaccharide._--Raffinose yielded the product

C_{18}H_{21}O_{5}.(NO_{3})_{11}.

_Starch_ yields the hexanitrate (C_{12}) by both methods of nitration.
The product has a high melting and decomposing point, viz. 184 deg., and
when thoroughly purified is quite stable. It is noted that a yield of
157 p.ct. of this nitrate was obtained, and under identical conditions
cellulose yielded 170 p.ct.

_Wood gum_, from beech wood, gave a tetranitrate (C_{10} formula)
insoluble in all the usual solvents for this group of esters.

The authors point out in conclusion that the conditions of instability
and decomposition of the nitrates of the monose-triose series are
exactly those noted with the cellulose nitrates as directly prepared and
freed from residues of the nitrating acids. They also lay stress upon
the superior stability of the nitrates of the anhydrides, especially of
the ketoses.

NITRATED CARBOHYDRATES AS FOOD MATERIAL FOR MOULDS.

THOMAS BOKORNY (Chem. Zeit., 1896, 20, 985-986).

(p. 38) Cellulose trinitrate (nitrocellulose) will ser