ARTIFICIAL SILK 41 



used in warps, but this objection will no doubt be over- 

 come. 



Mantles for the incandescent gas light are manufactured 

 of artificial silk, it being found that the salts of the rare 

 metals can be mixed with the collodion with greater 

 economy than with any other thread. 



For braids and such classes of trimmings it is much more 

 brilliant; for covering electric wires and all electric work 

 it is better. Large works are in operation at Besangon, 

 in France, producing 7,000 pounds per week; but the de- 

 mand is so great that they are making extensions to their 

 works to enable them next January to produce 2,000 

 pounds per day. The production at Sprietenbach is 600 

 pounds daily. Other factories are about to be established 

 in Belgium and Germany. 



Collodion silk can never replace natural silk in articles 

 where warmth is required, its composition being vegetable, 

 and that of silk analogous to horn and hair^or wool. The 

 artificial product is to be preferred, being more durable 

 than the natural when the latter is weighted in the dyeing 

 up to 100 per cent, in colors, and as high as 300 per cent, 

 in black. 



