CHAPTER THE NINTH, 
COCOONS OF PURE SILK. 
The faculty of spinning silk is brought to 
perfection by a species of caterpillar, with a 
smooth skin, and a green or yellow body, called 
the silkworm. It has so plentiful a supply of 
gum, that it needs no other material for its 
cocoon, but makes it entirely of silk. Indeed 
out of its superabundant store, it weaves two co¬ 
coons, one within the other. The inner one is the 
finest and most valuable, and is reeled off without 
any trouble; but the outer one is of coarse rough 
threads, and is so ravelled that it cannot be 
wound, and is known by the name of flos-silk. 
The silkworm intends the outer covering as 
a protection from the rain, for in a natural state, 
it would hang its cocoon under a tree; and 
though it is housed and sheltered, it never departs 
from what it has been taught by instinct. 
