2 28 On the Ainmal Calculus. . 
more and more in the Bladder. And thus by 
Changes from very hot to fudden cold, fatal 
Coagulations of the Blood are frequently made. 
6, If there be any thing in the common 
Notion, that laying on one's back, contributes 
to the Increafe of Gravel in the Kidnies, by 
heating of them, then this Experiment will 
fliew one Caufe which may contribute to it. 
Tho' I fufpeft that a principal Caufe of the 
firft beginning of the Growth of Gravel in 
the Kidnies, is owing to the horizontal Pof- 
ture we are in when we lay in Bed : In which 
Pofture one of the Kidnks being lower than 
the Bladder when we lay on one Side, and 
both the Kidnies when we lay on our Back 5 
the Pelvis or Cavity of the Kidnies becomes 
thereby the Sink for the tartarine Parts of the 
Urine to fettle in. And the Urine being in 
that Poflure propelled by the Kidnies with a 
Force not only equal to the perpendicular 
Height of the Bladder above them , but alfo 
with a Force fufficient to dilate the Bladder 
and circumambient Parts of the Abdomen*^ 
the Urine muft needs prefs (efpecially when 
the Bladder is in a good Degree full) with a 
confiderable Force againd the Orifices of the 
excretory Guts of the Kidnies \ whereby the 
Progieis 
