x P r e f a c e .
In the third chapter, the moft improved mierofcopes, and fome-
others which are in general ufe, are particularly defcribed; no
pains have been fpared to leffen the difficulty of obfervation, and
remove obfcurity from defcription; the relative advantages o f
each inftrument are briefly pointed out, to enable the reader to
I'd eft that which is beft adapted to his puffuits. The method of
preparing different objefts for obfervation, and the cautions
seceffary to be obferved in the ufe o f the microfeope, are the-
fubjeft o f the fourth chapter..
When I firft undertook the pr-efent effays, I had confined raj?--
felf to a re-publication o f my fathers work, entitled, Microgia-
phia Illuftrata; but I foon found that both his and Mr. Baker’s,
tracts on the microfeope were very imperfedi. Natural hiftory
had not been fo much cultivated: at the period when they wrote^
as it is in the prefent day. T o the want o f that information
which is now eafily obtained, we may,, with propriety, impute:
their errors and. imperfeSions, .1 have endeavoured to remedy
their defeats, by arranging the fubjefts in fyftematic order, and;
by introducing the microfeopic reader to the fyftem of Linnaeus*;
as far as relates to infedts : by this he will learn to difcriminate
one infeft from another, to characterize their different parts, and-
thus be better enabled to convey inftruCtion to others,, and to>
avoid error himfelf.
As,the transformations which infeCis undergo, conftitute a principal
branch of their hiftory, and furnifh many objefts for
the microfeope, I have given a very ample defcription of them;
the more fo; as many microfeopic writers, by not confidering
thefe changes with attention, have fallen into a. variety of miftakes..
Here
Here I intended to flop ; but the charms o f natural hiftory are fo
feducing, that I was led on to deferibe the .peculiar and
flriking marks, in the oeconomy of thefe little creatures. And
fliould the purchafer of thefe effays receive as much pleafure in
reading this part as I did in compiling it ; fliould it induce him
•to fludy thi's branch o f nature ; nay, fliould it only lead him to
read the flupendous work o f the mod excellent Swammerdam,-
he will have no reafon to regret his purchafe, and one o f my
wartoeft wiflies in compiling it will be gratified.
In the next chapter I have endeavoured to give the reader feme
idea of Mr. Lyonet’s “ anatomical and microfcopical defcription
o f the coffus, or caterpillar of the willow,” As this book is but
little known in our country, I thought that a fpecimen o f the indefatigable
labour o f this patient and humane anatomift would be
acceptable to all lovers o f the microlcope ; and I have, therefore,
appropriated a plate, which, while it {hews what may be effefted
when microfeopic obfervation is accompanied by patience' and
induftry, difplays alfo the wonderful organisation o f this infeft.
This is followed by a defcription o f many mifeellanêous objefts ;
objefts, of which no idea could be formed without the affiftance
o f glaflès.
T o deferibe the frefh-water polype, or hydra ; to give a ffiort
hiftory o f the difcovery of thefe curious animals, and fome account
of their Angular properties, is the bufinefs o f the fucceed-
ing chapter. The properties o f thefe animals are fo extraordinary,
that they were confidered at firft to be as contrary to the common
courfe o f nature, as they really were to the received opinions o f
animal life. Indeed, who can even now contemplate, without
b 2 aflonifh