ions of the
capillary orifice and concentration of the solution. The technical idea
involved in the spinning of artificial fibres is an old one. Reaumur (2)
forecast its possibility, Audemars of Lausanne took a patent as early as
1855 (3) for transforming nitrocellulose into fine filaments which he
called 'artificial silk.' The idea took practical shape only when it
came to be used in connection with filaments for incandescent lamps. In
this connection we may mention the names of the patentees:--Swinburne
(4), Crookes, Weston (5), Swan (6), and Wynne and Powell (7). These
inventors prepared the way for Chardonnet's work, which has been
followed since 1888 with continually increasing success.

At this date the lustra-celluloses known may be divided into four
classes.

1. 'Artificial silks' obtained from the nitrocelluloses.

2. 'Lustra-cellulose' made from the solution of cellulose in
cuprammonium.

3. 'Lustra-cellulose' prepared from the solution of cellulose in
chloride of zinc.

4. 'Viscose silks,' by the decomposition of sulphocarbonate of cellulose
(Cross and Bevan).

GROUP 1. The early history of the Chardonnet process is discussed and
some incidental causes of the earlier failures are dealt with. The
process having been described in detail in so many publications the
reader is referred to these for details. [See Bibliography, (1) and (2),
(3) and (4).] The denitrating treatment was introduced in the period
1888-90 and of course altogether changed the prospects of the industry;
not only does it remove the high inflammability, but adds considerably
to softness, lustre, and general textile quality. In Table I will be
found some important constants for the nitrocellulose fibre; also the
fibre after denitration and the comparative constants for natural silk.

TABLE 1.

_______________________________________________________________________
| | | |
| | Tenacity | Elasticity |
| | (grammes) | (% elongation) |
|__________________________________________|___________|________________|
| | | |
| Nitrocellulose according to Chardonnet | | |
| German Patent No. 81,599 | 150 | 23 |
| The same after denitration | 110 |