SILK-WORMS. 337 
although many speculate and Imagine it profitable, 
buying them at a low rate. 
The silk drawn from diseased cocoons is never 
so fine as that given by the perfect and healthy 
cocoon. 
Eight hundred and sixty cocoons of the black 
chrysalisweigh a pound and a half. 
The cultivator thus loses two-thirds, or three - 
fifths, upon this quality of cocoon. 
I must here state, in speaking of these three 
sorts of cocoons, that I have only made my expe- 
riments upon such cocoons as were brought to me 
from various places ; therefore my calculations 
may very possibly differ from those of other ob- 
servers. 
I will close this paragraph by the following re- 
mark. The art of spinning or winding the silk 
from the cocoon, is as yet entirely in the hands of 
people as ignorant as those who have hitherto 
reared the silk-worms. 
For instance, it is a well-known fact, that of two 
spinners, spinning each 7^1bs. of cocoons of the 
same quality, one will extract constantly eight 
ounces of silk, whilst the other will only draw 
six ounces and a half, and perhaps less still. There 
are even spinners so ignorant, that in giving con- 
stant jerks and strokes of the handle, they destroy 
several layers of silk enveloping the cocoon : 
a 
