SILK-WORMS. 
35 
It will be seen that this operation requires 
much care and attention ; but as the object is to 
hatch the eggs of the silk-worm at the most fa- 
vourable time to ensure success, this operation 
maybe considered as most essential. 
Those who among us have reared the silk-worm, 
seem to have found, and still to find, it difficult 
to bear in mind the difference between our cli- 
mate and the native warm climate in which the 
silk-worm originated. Obliged to have recourse 
to art to supply the deficiency of our climates, 
and to equal the advantages of those that are 
warmer, we have found the necessity of fixing 
upon some unerring method of timing the birth 
and rearing of the silk-worm, so as to be enabled 
to preserve them in health and vigour at the pe- 
riod most suited to our means and interest. 
What has been done towards this? In past 
times the cultivators of silk-worms imagined that 
the silk-worm might be hatched at random, and 
spontaneously ; and that if it were necessary to make 
an artificial climate, it was enough to use the heat 
of manure, or beds, or the natural heat of the 
body, or the kitchen fire, fyc., and similar means. 
It is now allowed that these methods, at best 
uncertain, are often pernicious to the insect. Ex- 
perience having shewn this, the result has been 
general discouragement ; we must not therefore 
be surprised to observe clear proofs of the destruc- 
