42 QUEEN'S QUARTERLY. 



perties. Camphor possesses the pecuHar property of depriving col- 

 lodion cotton and guncotton of their combustible and explosive 

 qualities. Celluloid is insoluble in water, and on this account is suit- 

 able for making domestic articles such as knife handles. Celluloid 

 can be rolled, polished, pressed, cut and hammered, and can also be 

 kneaded at a temperature of 145°C., so that occasionally it may take 

 the place of metals, stone, wood and wax. There are very few in- 

 dustries, in fact, in which this substance does not find employment 

 in some form or other. 



When cellulose is dissolved in a hot concentrated solution of 

 zinc chloride, we get a thick syrup which may be forced through 

 narrow orifices into alcohol, which precipitates the cellulose from its 

 solution in fine threads which may be carbonized, and used for fila- 

 ments for incandescent lights. Again, a solution of cellulose in am- 

 moniacal copper oxide is used for " surfacing " paper or cotton 

 fabrics, rendering them waterproof, and resistant to mildew and 

 insects. Such products are called " Willesden " goods, and are much 

 used for coverings of express wagons and busses. 



Within a comparatively short space of time an entirely new in- 

 dustry has arisen, that of the manufacture of artificial fibrous mate- 

 rials from cellulose, destined to provide the textile industry with a 

 new material, artificial silk, already largely used. Various methods 

 fbr making artificial silk are employed. One favorite method con- 

 sists, briefly, in causing a solution of collodion cotton in a mixture of 

 alcohol and ether to be forced, while hot, through capillary tubes, 

 whence it issues into a cooling vessel in fine threads which harden 

 at once. These threads are_ still explosive and of course unsuitable 

 for wearing apparel. They must undergo a de-nitrating process 

 which is accomplished by treating them with suitable reducing 

 agents. By again treating them with ammonium phosphate they are 

 rendered practically incombustible, thus giving us an article almost 

 identical in chemical composition with the original cotton from which 

 it was produced, but differing widely from it in appearance, since it 

 now has the appearance of natural silk and possesses a lustre equal 

 to, if not greater than, the natural article. Another method is the 

 " viscose " process by which wood pulp is caused to react with caus- 

 tic soda and carbon disulphide, forming a substance popularly called 

 " viscose," soluble in water to a viscous liquid which may be spun 

 into thread and cloth. This cloth, strange to relate, rapidly decom- 

 poses into caustic soda, carbon disulphide and cellulose again, thus 



