SILK-WORMS. 
167 
Ninth Day of the Fifth Age. 
(Thirty-first of the Rearing of the Silk-worm.) 
The silk-worms this day need 495 pounds of 
leaves, which must be distributed as it may be 
wanted. 
The yellow hue of the silk-worms grows deeper, 
their backs shine more, and in some of them the 
rings assume a golden appearance. 
The muzzle is become of a brighter red than it 
was in the beginning. 
From time to time a gentle fire should be light- 
ed, particularly in the night ; twice a day the fu- 
migating bottle should be passed through the 
laboratory ; the ventilators should never be shut 
when the fire is lighted, nor indeed at all, that the 
air may be renewed entirely. 
In a well-constructed laboratory, atmospheric 
variations need not be feared, which otherwise 
might be fatal to the silk-worms. (Chap. XIII . ) 
Since I first reared silk-worms, I have seen 
them exposed to every variation of seasons, and 
to many accidents that might have proved inju- 
rious to them ; however, my practice of rearing 
them was such, that I have always preserved them 
full of health and vigour. 
Let us now take the general result of what we 
have stated in this paragraph. In the course of 
about thirty days, in which the silk-worms have 
