^ ^ 3 ^? > 
the Blood, but more particularly the Power of Mercu- 
ly in the Cure of a Gonorrhea or Pox ; which are all 
lb eafily explained jby the actraclive pov\^er of Matter, 
that now no body can doubt of the truth of a Principle 
lofimple, which yet like a Mailer Key, opens the Works 
of very different contrivances, and difcbfes an Unifor- 
mity in all the Operations ol Nature : So that every 
one may fee and read the fame thought and hand in the 
contrivance and framing of every part of the Uni- 
verfe. 
Having given us the Method by which the feveral 
forts of Fluids are formed in the Blood before they are 
leparated from it, he then explains the way by which 
thele Lic^uors are lecerned by the Glands, and he proves, 
that the Oi ifices of all the Glands mult be circular, and 
that they can only diher in magnitude; and therefore 
all the Particles that arrive at the Orifice of any Gland, 
and are of a lefs Diameter than that of the Or.fi ce, will 
entei the Gland: So that if tliei*e were no other contri- 
vance in it, the Fluid which contains the biggell Parti- 
cles, will likewife confill of all the Particles of the other 
Secretions ^ but this inconveniency is obviated, bv ima- 
gining feveral Tubes to arife from the fide of the'Canal 
or Dud of the Gland, whole Orifices are of ludi De- 
menfions, that they will admit only Particles, which 
are fmaller than thofe that are to be fecerned by the 
Gland ; and a great many of them a'rifing from the fides 
of the Canal, throughout its whole Circumvolution 
will carry back to the Blood the Particles which are of 
a lels Diameter than thofe have, which are to be dil- 
cerned ; fo that there will at leall: remain in the Gland' 
only thefe Particles, with fuch a proportion of the wa- 
try Fluid, as is necelfary for the proper fluidity of the 
Liquor to be fecerned. 
In the Dilcourfe on the quantity of B’ood, he proves 
that the common Opinion that there are but i 5 or 20 
. z Founds 
