2 52 
THE ART OF REARING 
peat, that whenever it is strictly followed up, the 
silk- worms will never suffer disease; and that, on 
the contrary, whenever it is departed from, they 
will be exposed to the attacks of those disorders 
I am going to describe. 
1 . Diseases which arise from some Defect in the 
Eggs, or some Error in the Preservation of 
them. 
1. When the apartment destined for the com- 
ing forth, coupling, and laying of the eggs of the 
moth is too cold, the impregnating liquid will not 
be perfected and developed only in scanty propor- 
tions, at a temperature of only 54° or 59°, and 
consequently does not sufficientlv act upon the 
eggs, to give them the ashen colour which in the 
course of 15 or 20 days alone indicates the perfect 
impregnation. The unimpregnated eggs produce 
no worms, and those imperfectly impregnated, 
bear in them the seed of diseases that destroy the 
silk-worm in various stages of its existence. 
2. When the tenqoerature of the said apart- 
ment is too hot (77°, 81°.) In this temperature, 
if the male delays coupling, it looses much of the 
impregnating liquid. If united to the female too 
soon, upon issuing from the cocoon, she has not 
time to evacuate a superabundance of liquid mat- 
ter, with which she is loaded. She is therefore 
