(seq. 123)

57 Lect. 4

afterwards enlarge with the Growth of the Animal
Further Arteries in different Parts are of different Texture,
the Secretory Vessels may be so likewise, many Things may have
an Effect upon Secretion, as the Blood brought by the Vena
Portarum from the Bowels, & is supposed by Physiologists to
come prepared for that Secretion. Also from the Nature of the
Aliment the Secretion will be affected, & it may be assisted or alt-
ered by the Reservoir; as in the Bladder of Urine, the more watery
Part is taken up, & the Oily earthy excrementitious Part is thrown
off. Something in Life is necessary to assist Secretion therefore
after Death, it is not to be imitated - There are 4 different
States in the Process of Secretion - 1^st. A Preparation of Blood
as that from which the Gall is secreted undergoes A Preparati-
on by passing thro' the abdominal Viscera, & it is said, that the
Blood in the Porta is bitter, before it gets into the Liver -
2^d. The actual Separation made in Secretory Vessels by their diffe-
rent Dimensions - 3^d. An Absorption of the thinner Parts or
an Addition of something to the Secreted Fluid. 4^th. & lastly the
Excretion out of the Body, as the Bladder of Urine or Expulsion
from the Reservoirs to the Part, where it is wanted or Resump-
tion of it into the Body again, some Secretions being only occasionally
wanted, as the Semen &^c, also the Milk in the Breasts, which if
not drawn out generally becomes troublesome in y^e 3^d. Day.