t 68 ] 
CHAP. I 
Of the Animalcules in Fluids *■ 
H E fmalleft living Creatures yet 
A known are the Animalcules in Fluids.; 
whereof many Kinds have been difcovered 
by the Microfcope of fuch an exceeding Mi- 
nutenefs, that a Million of them w r ould not 
equal the Bignefs of a large Grain of Sand ; 
, and it is probable, there may be numberlefs 
Species of a Size much lefs than thefe. It is 
alfo likely, that there are as many, or even 
more Kinds of thefe Invijibles (if I may ufe 
the Term) than of thofe whofe Size is dis¬ 
cernible by the naked Eye. Here, therefore, 
is Abundance of Scope for Enquiry and Ad¬ 
miration, lince every Drop of Water, or 
other Liquor (excepting Oils and Spirits) 
either does already, or, upon Banding ex- 
pofed a few Days, will appear full of living 
Creatures , of various Sizes and Forms. Some 
Kinds of thefe Animalcules feem to be really 
Fifh, and are natural Inhabitants of the Wa- 
ter all their Lives : others live there but oc- 
cafionally, in the Manner of Gnats, which, 
from Eggs dropped by their Parents in the 
Water, become fwimming x^nimals; but 
after a while fhed their fkins, appear in a 
Form that bears no Refemblance to what 
they 
