IMPROVED. i-t 



befides that Liquors are fufceptible of all Figures, 

 and that Bodies of any Figure, and a leffer Dia- 

 meter than that of the Gland, will pafs through ; 

 e-^-en a Body of a fimilar Figure, and equal Dia- 

 ameter with that of the Orifice of the Glands, may 

 be prefented innumerable Ways, aad not be able to 

 pafs through, whilft there is only one Way it can 

 pafs. 



I fay that all the Vefiels in an Animal Body are All th2 

 Conical or Cylindrical, and confequently there is no ^ ^^^1^ '» 

 Difference in the Figure of their Orite; for, the^J'^^^^^^^^ 

 Preffure of a Fluid being always perpendicular upon or Cylindri- 

 the Sides of the VefTel that contains it, and equal at cal. 

 equal Heights of the Fluid, if the Sides are foft and 

 yielding they mufl be equally diflended or llretched 

 out ; that is to fay, a Se<5lion perpendicular to the 

 Axis of the VefTel muft be a Circle, and confequent- 

 ly the \^efrel be either Cylindrical or Conical : And 

 this is agreeable to the Accounts of the niceft Ana- 

 tomiils, who tell us, that a Gland is nothing elfe. 

 but a Convolution (or Vvinding together in a Bundle) 

 of fmall Arteries, whofe laft Branches are Cylindri- 

 cal, or, which is the fame Thing, Part of an infi- 

 nitely long Cone. A Gland therefore being no- 

 thing elfe but a Branch of an Artery, whofe farthefl 

 Extremity becomes the Excretory Duel or difcharge- 

 ing Pipe of the Gland, it is next to be known how 

 fuch a Strudure can feparate from the Blood only 

 fome of its Parts, and how different Glands may 

 feparate different Parts of the Blood. 



If fuch a Fluid then is to be drawn off, as con- 

 fifls of the fmallefl Particles of the Blood, let that 

 ■Orifice of the Gland, which is inferted into the Ar- 

 tery of which it is a Branch, be fo fmall as to ad- 

 mit only the fmallefl Particles of the Blood, then 

 thefe, and thefe only will enter this Gland, and the 

 Fluid, Vv'hich pafTes out at the other Extremity of 

 the Tube or the Excretory Duel, iiiufl be fuch as 

 is required, 



I 2 -if 



