PREFACE. 
XT 
thing of confequence in every branch of 
that part of natural hiftory, and affords 
hints for various difcoveries, hints that muft, 
if purfued, produce many confiderable im- 
provements in phyfic, hufbandry, and 
oeconomy. 
He has publifhed a Materia medica fo far 
as relates to plants, in which he has under- 
taken to determine many fpecies common- 
ly ufed but not fufficiently afcertained, 
adding throughout in the fhorteft manner 
poffible what he has found to be ufelefs or 
efficacious, and as he affures us never highly 
recommends any without being thoroughly 
convinced of their vertues by his own expe- 
rience in the hofpitals where he prefided* 
Some of thefe medicines have not yet, i be- 
lieve, been received into our Chops, but they 
may poffibly deferve confideration. 
In the laft edition of his Syftema nature 
he has mentioned above 1500 fpecies of in- 
fers, has claffed them all, divided them 
into genera and fpecies, defcribed them as 
to the minuteft parts fo far as was neceffary 
to diftinguifh them, marked the places 
4 where 
