, 6. J 
frefh pump water than in any other, 
In clear river water they appear 
later, lefs in number and in fize; 
lefs fo in rain water, and the leatt 
of allin boiled water, in ftagnating, 
and in diftilled water. 
They are not produced by the 
warmth of the fun rarifying the 
“air adhering to the leaves; Sy 
Kinds of leaves, produce them almoft 
as foon as plunged under water, 
though the water be very cold, and 
the leaves warm from the fun-fhine 
be plunged in it. - 
See a hot DDS gc Son ots 
ters but thofe thie rea — do 
‘not fhrink in or difappear by the 
cold of the night. 
As foon as the fun begins to dif 
fule its warmth over the furface of — 
fe earth in the fpring, and to pro= 
: mote 
