O F S I L K. 6^ 



to the raifing and ailturfe bf fevcral other 

 trees ; and though iff riiany places there 

 ^re things mentioned only as probable 

 conjectures, it is hoped they will afford 

 Ibme foundation for ufeful trials, which 

 however fliould always proceed with cau- 

 tion, and not be fnade in fuch a large 

 manner, as to become extenfively danger- 

 ous ; it is thus that experiments become 

 ufeful. But if they are made all at once, 

 and in a very extenfive manner, then, 

 tliough they fhould be founded in reafon, 

 they will moft commonly prove abortive, 

 becaufe fomc minute circumftance will be 

 omitted, while the attention was engaged 

 wholly on whatVas indeed more material, 

 but not entirely fufficient for the fuccefs of 

 the trial ; and it is chiefly for want of a 

 prudential conduft, that experimentors 

 have often fuffered, both in their fortunes 

 and in the opinion of the world. 



F THE 



