The Magnitude of the Particles of the Blood must be increased either by
the Union of a greater Number of them than in a Natural State; Or by the
Alteration of their Figure, by which their Surfaces become larger than
before.
_Demonstration._
This is evident from the Observations of _Lewenhoeck_ and _Malpighius_
on the perspirable and other ultimate Vessels, which are visible by the
Microscope, and consequently larger than the Orifices of the Lacteals,
which the best Glasses will not discover. Whence it will follow, that no
Particle can pass this way into the Blood, which single can obstruct the
Vessels, and consequently this Effect can only be produced by the Action
of the Particles upon each other, _viz._ either by the Union of a
greater Number, or some Alteration in their Figures, whereby their
Surfaces become larger than before. Thus the Globules of the Blood as
appears by the Microscope, are nearly of a Spherical Figure, which being
the most capacious, as well as most apt to constitute a Fluid Body, by
touching in the fewest Points The farther any Particles deviate from
this Figure, the more likely they will be to obstruct the Vessels, and
_vice versa_.