vi DEDICATIO N. 
It is fomething more than an hum* 
dred and twenty Years fince the 
Microscope was happily invented; 
and to the valuable Difcoveries made 
thereby, we Hand indebted, as the 
following Sheets will fhew, for a great 
Part of our prefent Philofophy. In 
fuch a Length of Time, it is howe¬ 
ver probable, many more Advantages 
might have been reaped from it, had 
not feme Difficulties and Difcotifage- 
xne.ji.ts prevented its general Ufe. 
At the Beginning it was confined 
to very few; who, making a Secret 
of it, endeavoured all they could to 
keep it to themfelves ; and, when it 
be da me a little more publick, the 
Price was fixed fo high, that the moft 
Curious and Indufirious, who have not 
always the greateft Share of Money* 
could not conveniently get at it. 
Of 
