Of Anlmalculd in "Fluids', 125 
forms, fitch a regular procefs being obferved in them, and 
eonflant uniformity in their appe&rance, makes it pro¬ 
bable that moft of them are produced from the fpawn 
of fome invifible volatile parents, and generated like 
gnats and feveral other forts of flies, which are bred and 
.undergo feveral changes in the water before they tak£ 
Tying j that fome of them originally may be water in¬ 
fers, or really fifh, fmall enough to be raifed in fpawn 
with the vapours, and to fall down again in fain, and 
to grow and breed in water that is kept. 
It has been thought that thefe minute flies, which 
hover every way in the air, when they find a fluid flored 
with convenient nourifhment far their future offspring, 
refort to it in fwarms to lay their eggs, which being foon 
hatched, the animalcula produced therefrom fwim about,, 
and live happily, till grown to a certain fize, change 
their forms, take wing and fly away. 
If the infufion is covered only with a fine lawn or 
ffiuflin, few animalcules will be found therein; but if 
it {lands open it wdll be full of life in a few days : in 
the leaf! drop taken from the furface of fuch infufion, the 
microfcope will difcover millions of living creatures. 
Of eels, ferpents, or little worm-like animalcula, 
found in vinegar and pafte. 
I F vinegar be expofed to the open air but a few days 
in hot weather, it will abound with eel-like animal¬ 
cula, reprefented by fig. 197. two of which are feen at 
A, making equal undulations, fometimes four or five are 
feen to move in the fame manner; at BBBB, are 
fiiewn four others differently coiled, they coil and uncoil 
themfelves with a fuprizing fwiftnefs, at C is a repre¬ 
fen Cation 
