Or rue SILK-WORM. 359 
move, and we make ufe of thefe experiments to fee if 
they have been killed in the oven. 
The worm dries the older it grows, fo that the fame 
quantity, or the fame number of cocons decreafes daily in 
weight. The cocons which enclofe the male butterfly 
have more filk at the extremities, than thofe which con- 
tain the females; but it is very difficult to perceive this 
difference, the moft fkilful connoiffeurs will miftake at 
leaft twenty in a hundred. 
When the worm wants to break his way through, he 
pierces the cocon, firft wetting it a little in order to gnaw 
it the more eafily; he has then only to ftrip off his upper 
coat, under which he has another quite white, with wings. 
When he comes out, his wings, which at firft appear 
very {mall, open and difplay themfelves by little and lit- 
tle, and are entirely at liberty in an hour or two. As 
foon as born he feeks a female, and one would fay he is 
born again merely to propagate his fpecies, for he expires 
a very little time after having performed his function. 
Cuap. Ill. Of Cocons Royal, Perforated Cocons, and 
Soufflons. 
THE royal cocons are thofe which you have kept for 
feed. The worm makes a hole in them for his paflage, 
fo that they cannot be wound, and are in the fame clafs 
with the perforated cocons. 
Neither can the foufflons be wound, becaufe their thread 
being the produce of a weak, fick worm, it has not the 
gum it ought to contain. Befides they cannot be wound 
off, their thread being interlaced and entangled. 
The ufes you may make of thefe cocons are the follow- 
ing ; and firft for the 
Soufflons ; you muft let them boil for about half an 
hour in common water, after which you muft dry them. 
When they are quite dry you muft threfh them on the 
Lalig 2 floor 
