478 M E M O I R S e/^ the 
has ieen the blood circulate in veflels fo fmall, that if a par- 
ticle of land was divided in looocoo parts, one of thefe parts 
could not pals thro' the blood-veflcl, tho* fuppofed as pliable 
as a particle of blood : He tried all poflible means to difcover 
the oval particles of blood, when it circulates freely in the 
veins ; and for that end he pitched upon the fmallefl: blood- 
vefTels, but notwithftanding the niceft enquiry he could make, 
he could not be fatisfied upon that point 5 for Ibmetimes he 
met with an obfcure dark particle, and fometimes with a much 
clearer one 5 and when he call his eye upon the fmallefl vefifels 
in which the blood did not move, and feveral vefTels that he 
difcovercd upon the extremity of the fin, the particles were 
quite deilroyed, fo that he faw nothing but a fimple llagnating 
liquor, a little tinflured with a bilious colour. 
Plate XIII. Fig. 24. A B CD reprefents the oval particles of 
a falmon, that weighed above 90 pounds 5 A B reprefents the 
particles that appeared flat and broad, but did not face the eye 
direflly; thofe about C came ftreight upon the eye, and for 
the moll part had a little clear fort of a light in the middle, 
larger infome than in others; thefe panicles are heavier than 
the ierous liquor, in which they fwim, and which together 
with the particles conftitutes the blood. 
M. Lee-wenhoeck likewife put upon a magnify ing-glafs the 
blood of a very Imall buttj which was not mixed with any 
liquor 3 only the particles lay in their Serum^ which are repre* 
fented Fig. 25. between £ and F. 
Thefe particles, which are diflinguifhed by little fliining 
fpots in the middle, are delineated Plate XIIL Fig. %6 between 
G and H: Moreover M. Lee-i^^enboeck put the blood palled 
upon a glafs to a greater magnifying-glals, the thinner moiflure 
arifing from the ferous matter, and the oval-like blood being 
exhaled 3 lb thatfome fmall oval particles were to be feen, that 
were fo far from running into each other, that they did not 
touch, and plainly fhcwed that they confilled of C\x little glo- 
bular particles reprefented in Fig. 27 between I and K. 
In pariuance of this new obfervation, M. Lee-wenhoeck 
viewed the circulation of the blood with glalTes that magni- 
fied Hill more than any he had hitherto ufcd, and fo he plainly 
made out the oval particles, now the greater jhe magnifying 
glals is, the fwifter does the circulation of the blood appear in 
the veflcls ; and having retarded this motion, he employed 
two or three feconds of time in obferving the little veins ; and 
he found that in feveral fmall vcffels the oval particles were 
broke 
