PREFACE. xv 
D if cour aging his further Progrefs in 
the reft) I omitted it. 
Of the few Plants ftill retained in 
our prefent Catalogues , a great Part 
of their formerly experienced and com- 
monly known Virtues are omitted ; 
becaufe it is objeBed , that our An- 
ceftors after ibed far more Virtues to 
them than they really had , or de- 
ferved ; but then let it be confedered \ 
i . "That various ConJUtutions and Ha- y 
bits of Body do neceffarily produce a 
V ariety and Difference of EffeEls in 
Medicines on our Bodies , as we fee 
from daily Experience ; the Bilious 
require one Sort , the Phlegmatic ano- 
ther , the Melancholic a third ; grafts, 
corpulent Bodies , and helhc, atrophic 
Habits , muft be differently treated , 
and often in the fame Difeafe. 2. ‘The 
fame Diforders, in different Perfons , 
arife from very different Caufes, 
and fo challenge different 'Treatment , 
though the Difeafes are the fame. 
3. The fame Caufe often generates va- 
rious 
