. detailed 
20 
ing, which modify the established doses of med- 
icines, in numerous instances. ‘Nhe necessity 
insisted on, of being alive to all those qualify- 
ing and exasperating influences, in order fairly 
to obtain the medicinal value of any substance of the 
Materia Medica. 
Subsection 3. 
: The alphabetical order used in preference to 
_ the common method of teaching and writing on ~ 
_ the Materia Medica. Reasons of this preference — 
ailed from the following outlines:— : 
A long course of study of the Materials of the sci- i 
ence, has fully brought to my view the endless ano- ; 
malies, paradoxical assumptions, and contradictory — 
results, arising from any attempt to classify the 
articles termed Materia Medica, by any of the com- 
monly adopted systems. 
Berhaave arranged the numerous Medicaments 
according to the order of his botanical system. Lin- 
neus followed the order of his sexual system 
throughouthis Materia Medica. The injudicious na- 
ture of these arrangements proved, by an exposition 
of the discordant materials brought together. Dr. 
‘Murray in his Apparatus Medecaminum, follow 
the order of botanical affinity. Instances of hetero- 
geneous articles brought together under this s 
tem, by illustrations from all the orders. 
The arrangement of Cullen, that one, which ' 
all the attempts at scientific classification, is the 
most highly wrought, and carefully digested, pro- 
duces perpetual discordancies of theory and prac- 
tice ; of data and results ; of assumed discipline and 
insubordinate irruptions into the ranks of division— 
