316 
THE ART OF REARING 
If any persons who rears silk-worms have read 
this work but once, the observations I am going 
to make will spare their reading many of the 
chapters again ; the facts, when presented toge- 
ther, will besides make a deeper impression than 
when they are offered singly to the mind. 
I do not doubt, that some of my readers will 
think many of the things I intend stating useless, 
because they offer no pecuniary result for indivi- 
dual interest, which is the first aim of the art of 
cultivating silk-worms. 
But I must hope, that those who will bestow 
their attention upon the series of facts I present, 
will find an intimate, although perhaps not an ob- 
vious, connexion between them and those very re- 
sults which the cultivator of silk-worms purposes 
to attain. 
It may also appear strange, that I should have 
applied calculation to this art, with the same ex- 
actness and precision which might have been 
applied to certain and invariable objects of art ; 
whilst this art we treat of is subject to change, 
to the influence of numerous causes, and to altera- 
tion. But I thought it requisite to demonstrate 
the experiments reiterated for years, with the ut- 
most exactitude, by the certainty and precision of 
calculation, that my practice might offer steady 
and sure rules to direct the cultivator of the 
silk- worms who might be inclined to adopt it. 
