508 



THE SILKWORM 



The extei :or of the cocoon is composed of a kind of rough cotton 



like substance, called floss , 

 within this the thread is more 

 distinct and even ; and next to 

 the body of the aurelia, the 

 apartment seems lined with a 

 substance of the hardness of 

 paper, but of a much stronger 

 consistence. The thread which 

 composes the cocoon, is not 

 rolled regularly round, but lies 

 upon it in a very irregular 

 manner, and winds off first 

 from one side, and then from 

 the other. 



In the course of six or seven 



WWUHB. - - 



days, all the cocoons are gen- 

 erally formed: they are then taken from places where they had been 

 deposited, and divided into classes. The best are strong, and of a 

 pure, unspotted color. Some are white, and others yellow. The good 



ones are firm and sound, 

 of a fine grain, and have 

 both ends round and 

 strong. Those of a bright 

 yellow yield more silk 

 than the others. 



But the pale ones are 

 preferred, because thej? 

 take certain colors better, 

 and because, since they 

 contain less gum than the 

 others, they lose less than 

 those in boiling. 



Five or six days after 

 the cocoon has been de- 

 tached, the birth of the 

 moth is prevented, as the 

 insect would otherwise 

 pierce the shell, and 

 thereby render the co- 

 coon useless. To prevent 

 this, the cocoons are put 

 into long, shallow bas- 

 kets, covered up, and 

 baked for about an hour, 

 in a heat equal to that of an oven from which the bread is just drawn 

 After the baking, they are disposed in a proper manner on osier 

 shelves, distributed into stories, two or three feet distant from each 

 other. 



The whole thread, if measured, will be found about three hundred 



fc. * b. BUTTERFLIES. C. THE BOOS. (1. THE PUPA. 6. SILKWORM. 



