A better view of moft objects is obtained by a candle, or lamp,
than by day-light; it is more eafy to modify the former than the
latter, and to throw it on the obje£l with different degrees o f
denfity. From what has been faid, the reader will have obferved
the importance of being able to examine the objeft in the greatefl
variety of politions and appearances, which cannot he effcfted
with equal, convenience by arty miorofcope but the improved
lucemal.
Of the Preparation of Objects for the Mio'RpscofE.
In the preparation of objeffs, no man was morejfuccefsful nor
more indefatigable than Swammerdam, in minutely anatomising,
in patient invedigation, and in curioufly ’exhibiting the minute
wonders Of creation; he bands unrivalled; far exceeding all thofe
that preceded, as well as thofe which have Succeeded him.
Deeply impreffed and warmly animated by the amazing 'fcenes
that he continually difcovered, 'his *'?.eal in 'purfuit o f truth iwas
not to be abated by difappointment, or alarmed by difficulty ;
and was never contented till he had attained a rational and clear
idea o f the organization o f the objeft, !whofe ftrufiure he wilhed
to explore.
We have only to regret that we are ignorant o f the methods he
employed. T o difcover fhefe, the great Boerhaave examined
with a fcrupulous attention all the letters and manufcripts <6f
Swammerdam, and has communicated the refult of his refearches,
which, though but fmall, may enable us to form fome idea o f
this great labourer in the field o f fcience.
For differing of fmall infects he had a brafs table, which was
made by that excellent artid S. Muffchenbrock; to this table
were affixed two brafs arms, moveable at pleafure to any part of <
it. The upper portian o f thefe arms was conftrufled fo as to
have a flow vertical motion, b y which means the operator could
readily alter their height, as he faw moft convenient to his pur-
pofe; the office o f one o f thefe arms was to hold the little bodies,
and that of the other to: apply the lens or microfcope.
His microfcopes, or lenfes, were of various foci, diameters,,
and fizes, from the lead to the greateff, and the heft that could
be procured in regard to the exa&nefs o f the workmanfhip, and
tranfparency o f the fubbance. His way was, to begin hisobfer-
vations with the fmalleft magnifiers, and from thence proceed by
degrees to the greatefl. By nature and ufe he. was fo incomparably
dexterous in the management o f thefe inffruments, that
he made every obfervation fubfervient to the next, and all tend
to confirm each other, and complete the defcription.
His chief art feems to have been in conbrufting very fine
feiflars, and giving them an extreme fharpnefs; thefe he made
ufe of to cut very minute objefts, becaufe they didefted them
equally; whereas knives and lancets, let them be ever fo fine and
{harp, are apt to diforder delicate fubdances, as in going through
them, they generally draw after and difplace fome of the filaments-
His knives, lancets, and dyles, were fo very fine, that he could
not fee to- fharpen them without the abidance o f a magnifying
glafs ; but with them he could diffeft the intedines o f Bees with
the fame accuracy and didinftnefs that the mod celebrated ana-
' tomid does thofe of large animals. He was particularly dexterous-
6 in,