SILK -WORM. 277 



It is the middle portion of the cocoon, after removing 

 the floss or loose silk on the exterior, which is used in 

 our manufactures ; and the first preparation is to throw 

 the cocoons into warm water, and to 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 call 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 generally 

 unwound without breaking the thread, that the insect 

 spins the whole without interruption. It is popularly sup- 

 posed, 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.* 



The length of the unbroken thread in a cocoon varies 

 from six hundred to a thousand feet ; and as it is all spun 

 double by the insect, it will amount to nearly two thousand 

 feet of silk, the whole of which does not weigh above three 

 grains and a half: five pounds of silk from ten thousand 

 cocoons is considerably above the usual average. AVhen 

 we consider, therefore, the enormous quantity of silk 

 which is used at present, the number of worms employed 

 in producing it will almost exceed our comprehension. 

 The manufacture of the silk, indeed, gives employment, 

 and furnishes subsistence, to several millions of human 

 beings ; and we . may venture to say, that there is scarcely 

 an individual in the civilized world who has not some 

 article made of silk in his possession. 



In ancient times, the manufacture of silk was confined to 

 the East Indies and China, where the insects that produce 

 it are indigenous. It was thence brought to Europe in 

 small quantities, and in early times sold at so extravagant 

 a price, that it was deemed too expensive even for royalty. 

 The Emperor Aurelian assigned the expense as a reason 



* On a tort de croire que le bruit nuise a ces insectes, Hist. Nat. 

 Geuerale, vol. xiii. p. 170. 



