ae ee ea: 
It muft be granted that, but for the microfcope, the wonders of 
. ‘ © . . 
He minute creation, would be to us entirely unknown; our ideas could 
never fuppofe the exiftence of thofe animated forms which occupy 
the immeafurable fpace between an apparent atom and nothing. The 
myriads of animals, thoufands of times f{maller than a mite, muft 
evade our cognizapce, and be an aétual conviétion of their non- 
exiftence. 
But with all the utility that the microfcope can boaft, no inftru~ 
ment is fo likely to miflead the moft accurate obferver, particularly 
if not in thé habit of ufing it ; the variations of light, the difference of 
the magnifying powers, or the damage the glafles may meet with by 
accident, fuch as requires every one to examine with the greateft care; 
one degree of light may bring an objeé to view, whilft another may - 
entirely blend it with the fluid it exifts in; or one glafs may difcover 
-fpines on an objeét, another glafs might have reprefented perfectly 
{mooth ; it is therefore neceflary to begin with a fmall power, in pro- 
portion to the fize of the obje&, and to proceed to deeper mag~ 
nifiers after. — 
There is fome difference in our figure, and thofe either of Barbut, 
or of Baker, which appears chiefly from our ufing a fingle lens nearly 
of the deepeft power convenient to ufe. Our glafles were the 20th. 
and 30th of an inch focus. 
We very attentively examined the eyes, and found, not one, but 
two, placed near each other, on a fcale or plate of a black colour; 
hence arifes the appearance of a fingle eye by a fmall magnifying 
power. 
The tail prefents a forked appearance by a deep power, and the 
‘eggs are contained in two bags, one on each fide the tail. The co- 
jour varies probably in proportion to the nature of its food, to’ pale 
green, more or lefs of a red, or of a grey brown colour. 
Fic. 
