[ 3°6 ] 
globules are full of clouds, made by the fmoke of 
the lamp ufed in preparing; them, and the objefl can 
be feen only through the tranfparent parts of the 
globules, which makes it difficult to get a fatisfac- 
tory view of it.; this, with the trouble of adapting 
the objedls to the focus of the glafs, made me pre- 
fer our own lenfes for all the experiments mention- 
ed in thefe ffieets, except one ; and it is but doing 
juftice to the ingenious gentleman abuvementioned, 
to acknowledge, that the greater power of his glafies 
was found in that experiment more than to com- 
penfate for their want of diftindlnefs. 
Thefe particles of the blood, improperly called 
globules, are in reality flat bodies. Leeuvvhenhoeck 
and others have allowed, that in filh and in the 
amphibia they are flat and elliptical ; but in the 
human fubjeft and in quadrupeds alrnofl: all mi- 
Crofcopical obfervers have agreed in their being 
fpherical. When we confider how many ingenious 
jperfons have been employed in examining the blood 
with the bed; microfcopes, it will appear won- 
derful, that the figure of thefe particles fhould have 
been mifiaken ; but our wonder will be lefiened, 
when we confider how many obvious things are 
overlooked, till our attention is very particularly 
directed to them ; and befides, the blood in the hu- 
man fiabjeftand in quadrupeds is fo full of thefe par- 
ticles, that it is with great difficulty we can fee them 
feparate, unlefs we find out a method of diluting 
the blood. It is to fuch a difeovery that I attribute 
my fuccefs in this enquiry ; for, having examined 
the blood as it flows from the veffels of the human 
body, it appeared a con fu fed mafs, not withftan ding 
I fpread 
