3l6 CHAPTER 24. 
And In the laft^ on Gums, Exudations, and 
the methods of obtaining them. 
The objed: of Dioscorides being folely 
the Materia Me die a y he difculTes each fub- 
jeS: fpecifically, and in a feparate chapter, 
dividing the whole into five books ; ir^ which, 
as far as any order takes place, they arrange 
into aromatic, alimentary, and medicinal 
plants. His defcriptions are taken chiefly 
from coloiirp fize, mode of growing, com- 
parifon of the leaves and roots, with other 
plants wtU known, and therefore left unde- 
fcribed. In general they are fliort, and fre- 
quently inlufficient to determine the fpecies. 
Hence arofe the endlefs, and irreconcileable 
contentions, among the commentators. In 
this manner he has defcribed near 700 
plants ; to which he fabjoins the virtues 
and ufes. To Dioscorides all poflerity 
have appealed as decifive on the fubjed:. 
Pliny, who treats of plants from the 
twelfth to the twcnty-feventh book, inclu-- 
five, of his Hiftory,'' has drawn his re- 
fources principally from Grecian authors/ 
He is the hiftorian of antient botany, and 
recites the names of feverar hundreds, not 
pientioned 
