SILK-WORMS. 
213 
I cannot trace the origin of this error. Can it 
have been suggested by the silk-spinners for their 
own interest ? 
To enable me exactly to know and calculate the 
diminution of the weight in the cocoon, I carefully 
weighed, every day, 1000 ounces of cocoons, 
reckoning from the moment they completed their 
formation, until I perceived that some moths, by 
wetting the cocoon a little, indicated that they 
had pierced the envelope which covered the chry- 
salis, and were preparing to rend the cocoon. 
The following is the result of the daily decrease 
of the, 1000 cocoons, in a temperature between 71° 
and 73° : — 
Ounces. 
Gathered from the fagots and cleaned, the co- 
coons weighed 
. 1000 
First day following, the cocoons weighed . 
. 991 
Second day 
. 982 
Third day 
. 975 
Fourth day 
. 970 
Fifth day ...... 
. 93G 
Sixth day 
. 9GO 
Seventh day ...... 
. 952 
Eighth day ...... 
. 943 
Ninth day ...... 
. 934 
Tenth day 
. 925 
We find by this that the cocoons 
lose, in ten 
days, seven and a half per cent., by the desiccation 
of the chrysalis alone. The first four days they 
lose three per cent., or three-quarters per cent, 
a day ; in the last days they lose rather more, be- 
