226 
THE ART OF REARING 
You may employ, instead of a frame, paper, 
pasteboard, or any thing else, for the purpose of 
receiving the deposited eggs. I speak of frames, 
because they make a part of the description of the 
utensils necessary in the art of raising silk- 
worms. 
There are very few good cocoons that do not pro- 
duce a moth, and of these few the greater number 
consists of those whose hardness and smallness 
prevent the moth making a hole, by which to 
come forth. The proportion of weight between 
the cocoon that still contains the moth, and the 
empty one, but which is not yet perfectly clean, 
is as six to one, that is to say, from 28 ounces of 
• full cocoons 4 ounces can be obtained ; but 
from those which are burst, only three-quarters of 
an ounce. (Chap. XIV.) The relative weight of 
the two envelopes found in the open cocoon, and 
the open cocoon itself that has been well cleaned, 
is about as one to thirteen, or the two envelopes 
weigh in general half a grain, and the empty 
cocoon nearly six grains and a half. 
2. Separation of ihe Moths , and Laying of the 
Eggs. 
In the preceding paragraph I have supposed, 
when speaking of the union of the moths, that 
the number of males was equal to that of females, 
