SILK-WORMS. 
187 
expedition. First, taking away with the hands 
the litter that may be lying near the edges and 
clumps, then removing all the excrements that 
may remain either with the broom or dung- 
shovel, (fig. 25), or any convenient tool, care- 
fully cleaning every part of the wicker. 
It is beneficial to carry off, as quickly as possi- 
ble, every thing that tends to corrupt the air, or 
make it damp. 
6. Care of the Laboratory until the Silk-worm 
has completed its Fifth Age. 
1st. When the worms manifest a desire to rise, 
infinite care should be taken to prevent the 
temperature of the laboratory from falling ; 
it should be maintained between 68° and 71° 
that if the exterior air be cold, it may never 
directly strike upon the worms, that no cold blasts 
should reach them ; but, on the contrary, that a 
gentle circulation should be made from the top to 
the bottom of the laboratory, by means of the 
ventilators in the ceiling and floor, which must be 
opened more or less, according to circumstances ; 
and the air may be circulated from the contiguous 
apartments by opening the doors into them. 
These precautions are needless, when the exterior 
air is warm, and is not agitated by much wind. 
It is proved that any violent agitation of air 
cramps the worms, stuns them, causes them to 
