SILK-WORM. Sn 



fibres of the silk together (see p, 196). Mr Swayne 

 denies that the threads are broken at all, either by- 

 filing or solution; fijr he succeeded in unwinding a 

 whole cocoon from which the moth had escaped. The 

 soiling of the cocoon by a fluid, however, we may 

 remark, is no proof of the acid; for all moths and 

 butterflies discharge a fluid when they assume wings, 

 whether they be inclosed in a cocoon or not; but 

 it gives no little plausibility to the opinion, that " the 

 end of the cocoon is observed to be wetted for an 

 hour, and sometimes several hours, before the moth 

 makes its way out."* Other insects employ different 

 contrivances for escape, as we have already seen, and 

 shall still further exemplify. 



It is the middle portion of the cocoon, after re- 

 moving the floss or loose silk on the exterior, which 

 is used in our manufactures; and the first prepara- 

 tion is to throw the cocoons into warm water, and 

 stir them about with twigs, to dissolve any slight 

 gummy adhesions which may have occurred when 

 the caterpillar was spinning. The threads of several 

 cones, according to the strength of the silk wanted, 

 are then taken and wound off upon a reel. The 

 refuse, consisting of what we may cafl the tops and 

 bottoms of the cones, are not wound, but carded, 

 like wool or cotton, in order to form coarser fabrics. 

 We learn from the fact of the cocoons being gene- 

 rally unwound without breaking the thread, that the 

 insect spins the whole without interruption. It is 

 popularly supposed, however, that if it be disturbed 

 during the operation by any sort of noise, it Will 

 take alarm, and break its thread; but Latreille says 

 this is a vulgar error. "j" 



* Count Daudolo's Art of Rearing Silk-Worms, Eng. 

 Transl. p. 215. 



t On a tort de croire que le bruit nuise a ces insectes. Hist. 

 Nat. Gfn'ral., vol. xiii., p. 170. 



VOL. IV 27* 



