( 45* ) 
But however excellent thefe GlafTes may be judg’d, 
Mr. Leeuwenhoek's Difcoveries are not entirely to be 
imputed to their Goodnefs only : His own great Judg- 
ment, and Experience in the Manner of ufing them, 
together with the continual Application he gave to that 
Bufinefs, and the indefatigable Induftry with which he 
contemplated often and long upon the fame Subjed:, 
viewing it under many and different Circum fiances, 
cannot but have enabled him to form better Judgments 
of the Nature of his Objefts, and fee farther into their 
Conflitution, than it can be imagined any other Perfon 
can do, that neither has the Experience, nor has taken 
the Pains this curious Author had fo long done. 
Nor ought we to forget a Piece of Skill, in which he 
very particularly excelPd, which was that of preparing 
his Objeds in the befl Manner, to be view’d by the 
Microfcopej and of this I am perf waded, any one will 
be fatisfied, who (hall apply himfelf to the Examina- 
tion of fome of the fame Objeds as do yet remain be- 
fore thefe GlalTes at lead, I have my felf found fo 
much Difficulty in this Particular, as to obferve a ve- 
ry fenfible Difference between the Appearances of the 
fame Objed, when apply ’d by my felf, and when pre- 
pared by Mr. Leeuwenhoek, tho’ view’d with Glaffes 
of the very fame Goodnefs. 
I have the rather infifted upon this, as it may be a 
Caution to us, that we do not rafhly condemn any of 
this Gentleman’s Obfervations, tho’ even with his own 
Glaffies, we ffiould not immediately be able to verify 
them our felves. We are under very great Difadvantages 
for want of the Experience he had, and he has himfelf 
put us in Mind, more than once, that thofe who are 
