imits of dilution and corresponding effect, the
process allows of the production of either a 'bulk' or a 'condensed'
powder.

We prefer to use about five litres of the liquid to each one kilo. of
grain operated upon, as this quantity allows of the grains being freely
suspended in the liquid upon stirring. The grains are run into the
liquid, which is then preferably heated to the boiling-point for a few
minutes whilst the whole is gently stirred. Under this treatment the
grains assume a more or less rounded gelatinous condition according to
the strength of the liquid. There is, however, no solution of the
guncotton and practically no tendency of the grains to cohere. Each
grain, however, is acted upon _throughout_ and perfectly _equally_.
After a few minutes' treatment, water is gradually added, when the
grains rapidly harden. They are then freed from acetone and certain
impurities by washing with water, heating, and drying. The process is of
course carried out in a vessel provided with any means for gentle
stirring and heating, and with an outlet for carrying off the
volatilised solvent which is entirely recovered by condensation, the
grains parting with the acetone with ease.

_Stabilising cellulose nitrates._--The process is of especial value in
rendering stable and inert the traces of unstable compounds which always
remain in cellulose nitrate after the ordinary boiling and washing
process. It is of greatest value in the manufacture of collodion cotton
used for the preparation of gelatinous blasting explosives and all
explosives composed of nitroglycerin and cellulose nitrates. Such
mixtures seem peculiarly liable to decomposition if the cellulose
nitrate is not of exceptional stability (J. Soc. Chem. Ind., 1899,
787).

EMPLOI DE LA CELLULOSE POUR LA FABRICATION DE FILS BRILLANTS IMITANT LA
SOIE.

E. BRONNERT (1) (Rev. Mat. Col., 1900, September, 267).

V. ~USE OF CELLULOSE IN THE MANUFACTURE OF IMITATIONS OF SILK
(LUSTRA-CELLULOSE).~

(p. 45) _Introduction._--The problem of spinning a continuous thread of
cellulose has received in later years several solutions. Mechanically
all resolve themselves into the preparation of a structureless filtered
solution of cellulose or a cellulose derivative, and forcing through
capillary orifices into some medium which either absorbs or decomposes
the solvent. The author notes here that the fineness and to a great
extent the softness of the product depends upon the dimens