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OBJECTS TOR THE MICROSCOPE. 
the instances which occur of such imitations; and I shall only remai k 
that, generally speaking, these arms and instruments iu structure and 
finishing far exceed those which they resemble.” 
METHOD OF DISSECTING INSECTS. 
Swammerdam excelled in the preparation of insects. Neither diffi- 
culty nor disappointment could make him abandon the pursuit of any 
object until he had obtained a satisfactory idea of it. But, unhappily , 
few of the methods he used in preparing his objects for the micro- 
scope are now known. Boerhaave examined with the strictest atten- 
tion all the letters and manuscripts of Swammerdam which he could 
find; but his researches were far from being successful. The follow- 
ing are all the particulars which have come to the knowledge of tire 
Public. , , 
For dissecting small insects Swammerdam had a brass table, to 
which were affixed two brass arms moveable at pleasure to any part ot 
it. The upper part of these vertical arms was constructed in such a 
manner as to have a slow vertical motion ; by which means the ope- 
rator could readily alter the height as he saw convenient. One of 
these arms was to" hold the minute objects, and the other to apply the 
microscope. . . 
The lenses of Swammerdam’s microscopes were of various sizes as 
"■’ell as foci- but all of them the best that Could be procured both for 
the transparency of the glass and the fineness ot the workmanship. 
His observations were always begun with the smallest magnifiers, from 
which he proceeded to the greatest; but in the use of them he was so 
exceedingly dexterous, that he made every observation subservient to 
that which succeeded it, and all of them to the confirmation of each 
other and to tire completing of the description. Ilis chief art seems 
to have been in constructing scissars ot ail exquisite fineness, and 
making them very sharp. Thus he was enabled to cut very minute 
objects to much more advantage than could be done by knives and 
Sheets ; for these, though ever so sharp and line, are apt to disorder 
delicate substances by displacing some of the filaments and drawing 
them after them as they pass through the bodies; but the scissars cur 
them all equally. The knives, lancets, and styles he made use of in Ins 
dissections, were so fine that lie could not sec to sharpen them without 
the assistance of a magnifying glass; but with these he, could dissect 
the intestines of bees with the same accuracy that the best anatomists 
c an do those of large animals. He made use also of very small glass 
tubes, no thicker than a bristle, and drawn to a very fine point at one 
end but thicker at the other. These were for the purpose ol blowing 
