306 
THE ART OF REARING 
As to the aspect of the cultivators’ labo- 
ratories, there is no doubt the coldest is the best, 
and that which is most exposed to the wind ; and 
that they are better on the first, than on the 
ground-floor. But, however, if the improvements 
I have suggested are made, such places as are 
convenient may be employed with a certainty 
that the air will never, when my system is fol- 
lowed up, be stagnant, damp, or mephitic. 
One might be tempted to imagine that one of 
the causes that have contributed to the perpe- 
tuation of the use of the worst and most inconve- 
nient erections for the habitations of silk-worms is, 
there having now and then been collected a 
tolerably abundant crop of cocoons. It was 
never thought to be the effect of chance, or, more 
properly, the effect of the favourable variations 
of the weather. 
One year for instance, in which the season had 
been fine and dry, in consequence of a north 
wind, which blew much, it would not be sur- 
prising that the worms succeeded, although ill 
managed. 
We have an example of the benefit of con- 
stantly dry air, and of air constantly in motion 
renewed, in the sheds or barracks of the moun- 
tainous districts in which they rear silk-worms. 
They always are more successful than in the 
plains. 
We now find, that let the meteorological influ- 
