f
combination with water. Many attempts have been made to confer
water-resistance (18), but without success. Strehlenert has proposed the
addition of formaldehyde (19), but this is without result (20). In
reference to these effects of hydration, the author has made
observations on cotton thread, of which the following table represents
the numerical results:

Breaking Strain
Mean of 20 experiments

Skein of bleached cotton without treatment 825
Skein of bleached cotton without treatment, but wetted 942
Ditto after conversion into hexanitrate, dry 884
The above, wetted 828
The cotton denitrated from above, dry 529
The cotton denitrated as above and wetted 206

The author considers that other patents which have been taken for
spinning nitrocellulose are of little practical account (21) and (22).
The same conclusion also applies to the process of _Langhans_, who
proposes to spin solutions of cellulose in sulphuric acid (23) (24) and
mixtures of sulphuric acid and phosphoric acid.

GROUP 2. _Lustra-cellulose._--Thread prepared by spinning solutions of
cellulose in cuprammonium.

This product is made by the Vereinigte Glanzstoff-Fabriken, Aachen,
according to a series of patents under the names of H. Pauly, M. Fremery
and Urban, Consortium mulhousien pour la fabrication de fils brillants,
E. Bronnert, and E. Bronnert and Fremery and Urban (1). The first patent
in this direction was taken by Despeissis in 1890 (2). It appears this
inventor died shortly after taking the patent (3) The matter was later
developed by Pauly (4) especially in overcoming the difficulty of
preparing a solution of sufficient concentration. (It is to be noted
that Pauly's patents rest upon a very slender foundation, being
anticipated in every essential detail by the previous patent of
Despeissis.) For this very great care is required, especially, first,
the condition of low temperature, and, secondly, a regulated proportion
of copper and ammonia to cellulose. The solution takes place more
rapidly if the cellulose has been previously oxidised. Such cellulose
gives an 8 p.ct. solution, and the thread obtained has the character of
an oxycellulose, specially seen in its dyeing properties. The best
results are obtained, it appears, by th