PREFACE. xxi 
which afterwards cannot be fo ufed f 
And are not almofi all Phyfical Roots 
taken up either in the Spring-Tfime , 
when they begin to f prout , or after 
their Leaves are fallen 9 And what 
are unripe Seeds good for 9 1 8. Dif- 
ferent Mixtures will produce Effe&s 
different from the Simples ufed fepa- 
rately ; thus Elder-bark with Syrup 
of Poppies is fudorific ; the fame is the 
lixivious Salt of Alb- wood given with 
Diuretics. 1 9. "The "Time of giving 
them may likewife make a Difference ; 
for white Hellebore, given in a fmall 
Dofe t may be fafer on a full Stomach 
than on an empty. 20. Tfhe different 
Places of Growth of the fame Species of 
Plant make gome Difference in its Ef- 
feEls : Wild Arrach is drier than that 
in the Garden , which is cooler and 
inoifier : Sea Arrach vomits and purges 
more than either of the other. Englilh 
Tobacco is milder than thatofh.mtnca^ 
&c. 2i. Tfhe fever al Parts of the 
fame Plants very often have different 
EffeEls \ no Wonder then that we find 
