‘ 
46 AIDS TO THE STUDY OF PHARMACOGNOSY. 
barium) in Berlin has also begun worthily to follow the example, 
though not precisely in a pharmaceutical direction. 
C. Microscopical Preparations. Notwithstanding the im- 
portance of a knowledge of the inner structure of many medi- 
cinal substances, the preparation of objects for the microscope 
often requires such an expenditure of time as to interfere 
with its accomplishment. This is, however, so instructive (see 
p. 48) that it is only in cases of necessity, or for the purpose of 
supplementing individual work, that the purchase of micro- 
scopical preparations will be attended with substantial benefit. 
It must, nevertheless, be admitted that these preparations are 
now presented, especially in Germany, in an unusually attrac- 
tive and complete form. 
Il. LITERARY AIDS. 
The following list contains a selection of works which are 
adapted to quite extended requirements, but makes no claim to 
completeness, 
A. Medico-pharmaceutical Botany. Of ies iota works, 
the following deserve particular mention: 
Kosteletzky, ‘‘ Allgemeine medicinisch-pharmaceutische 
Flora,” 3 volumes, Prague, 1831-1834 (now sold by Hoff, © 
Mannheim). 
Geiger, Nees von Esenbeck and Dierbach, ‘‘ Pharmaceutische 
Botanik,” 3 volumes, Heidelberg, 1839-1843, 
Bischoff, ‘‘ Medicinisch-pharmaceutische Botanik,” Erlangen, 
1843; second edition, 1847. 
Svbleiden, ‘*Handbuch der medicinisch-pharmaceutischen 
Botanik,” Leipzig, 1852. 
Rosenthal, ‘‘ Synopsis plantarum diaphoricarum. Systema- 
tische Uebersicht der Heil-, Nutz- und Giftpflanzen aller 
Linder,” Erlangen, Enke, 1872. 
These works, which are excellent in their way, may, perhaps, 
occasionally still be consulted with profit; they are, however, 
more than replaced by the following: 
Luerssen, ‘‘ Medicinisch-pharmaceutische Botanik,” also un- 
