hloride to effect its
dissolution by digestion in the cold. (U.S. patent, 646,799/1900. See
also p. 59.)

_Industrial applications._--(a) _Vulcanised fibre_ is prepared by
treating paper with four times its weight of the concentrated aqueous
solution (65-75 deg. B.), and in the resulting gelatinised condition is
worked up into masses, blocks, sheets, &c., of any required thickness.
The washing of these masses to remove the zinc salt is a very lengthy
operation.

To render the product waterproof the process of nitration is sometimes
superadded [D.R.P. 3181/1878]. Further details of manufacture are given
in Prakt. Handbuch d. Papierfabrikation, p. 1703 [C. Hofmann].

(b) _Calico-printing._--The use of the solution as a thickener or
colour vehicle, more especially as a substitute for albumen in pigment
styles, was patented by E. B. Manby, but the process has not been
industrially developed [E.P. 10,466/1894].

(c) _Artificial silk._--This is a refinement of the earlier
applications of the solution in spinning cellulose threads for
conversion into carbon filaments for electrical glow-lamps. This section
will be found dealt with on p. 59.

(p. 13) (2) ~Cuprammonium solution.~--The application of the solution of
cellulose in cuprammonium to the production of a fine filament in
continuous length, 'artificial silk,' has been very considerably studied
and developed in the period 1897-1900, as evidenced by the series of
patents of Fremery and Urban, Pauly, Bronnert, and others. The subject
will also be found dealt with on p. 58.

* * * * *

(p. 15) ~Reactions of cellulose with iodine.~--In a recent paper, F.
Mylius deals with the reaction of starch and cellulose with iodine,
pointing out that the blue colouration depends upon the presence of
water and iodides. In absence of the latter, and therefore in presence
of compounds which destroy or absorb hydriodic acid--e.g. iodic
acid--there results a _brown_ addition product. The products in question
have the characteristics of _solid solutions_ of the halogen. (Berl.
Ber. 1895, 390.)

(24) ~Mercerisation~--Notwithstanding the enormous recent developments in
the industrial application of the mercerising reaction, there have been
no noteworthy contributions to the theoretical aspects of the subject.
The following abstract gives an outline of the scope of an important
technical work on the subject.

DIE MERCERISATION DER BAUMWOLLE.

PAUL GA