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It is probable, that, if the Surface of the medicinal 
Liquor be about a Foot higher than the Abdomen , it 
may be fufficient for the Purpofe. 
It were eafy to find the Force with which the 
Abdomen is diftended by the dropilcal Lympha, by 
feeing to what Height it arofe in a Glafs Tube fixed 
to th cTrochar-, which Tube being taken away, it 
might, I fuppofe, be fufficient to have the medicinal 
Liquor flow in from a leffer perpendicular Height, 
than that to which the dropfical Lympha arofe in the 
Glafs Tube. I am, , 
V. An ExtraSi of John Fothergill, M. D . 
Licentiate of the Royal College of Phyii- 
cians, London, his Effay upon the Origin 
of Amber. 
tw March i. jk FTER all that has been wrote upon 
1 743-4- fjk. t ^ ie Subject of Amber, its Origin is 
yet, in a great meafure, unknown. Several inge- 
nious Men have fearched into this Affair upon the 
Spot where the Amber is principally gathered : They 
have related their Obfervations with great Candour j 
they have given us the Conclufions they drew from 
the Fads they difeovered 5 yet without fatisfying us 
intirely about many Particulars, 
SIR, 
Tour humble Servant 
But, 
