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tive parts of vegetables, may not the well-attefled fa- 
lutary effects of the Coimbra extrad be owing to its 
greater quantity of thefe adive principles, particularly 
if we confider the large dofe it has been prefcribed 
in ? As thefe adive oily falts and rezins are foluble 
in fpirit of wine, we have the means of obtaining 
them from the extrad of our own Hemlock in fuffi- 
cient quantities for ufe, and without fatiguing the 
flomach with the naufeous inadive parts of the 
extrad. 
But as experience alone can fhew whether the 
virtues of the Hemlock refide in the whole extrad, 
or in the faponaceous parts foluble in fpirit of wine ; 
1 fhall content myfelf with propofing thefe few hints, 
until experiments fhall enable me to lay the other 
confequences of thefe affays with proper weight be- 
fore the Society. 
XXXIII. An 
