SILK-WORMS. 
127 
cal operator, because the art of rearing these in- 
sects cannot, as many others do, make rapid and 
sure strides towards perfection, without the aid of 
physical science. 
I do not intend here to give scientifical lectures, 
but to endeavour to make some truths obvious, 
which the intelligent cultivator may easily put 
into practice, to protect himself in all cases from 
those losses to which a man even of experience 
may be exposed, not knowing those truths. 
Wherefore, previous to resuming the description 
of the daily progress of the silk-worms, I will give 
a few practical observations. 
Should the worms die in the first age, the loss 
is trifling, because expense is not prolonged, and 
that the leaves provided may be sold, or disposed 
of : while, on the contrary, should the worms perish 
in the fifth age, the loss is considerable, leaves 
having been consumed, and labour paid, as well as 
other expenses; besides seeing the hopes of all that 
profit vanished which had been reckoned upon. 
It is then very needful to know the condition 
of the worms in the fifth age, to learn how to ma- 
nage, so as to ensure their health and strength 
against the attacks of atmosphere or other evils 
that assail them. 
As the silk-worms grow in the fifth age, they are 
liable to three evils, which attack them according 
to their strength, and to their distribution in the 
