340 Insect Architecture. 



into warm water, and to stir them about with twigs, to 

 dissolve any slight gummy adhesions which may have oc- 

 curred 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, con- 

 sisting 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 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.* 



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. When 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 for 

 refusing his empress a robe of silk ; and our own James I., 

 before his accession to the crown of England, had to borrow 

 of the Earl of Mar a pair of silk stockings to appear in before 



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

 vol. xiii. p. 170. 



