40 TREATMENT OF THE SUBJECT-MATTER. 
Jaborandi leaves, from the Brazilian Rutacea Pilocarpus pen- 
natifolius, and the leaves of Erythroxylon Coca, from Peru and 
Bolivia. 
The zealous endeavors of the eclectic school of medicine of 
North America to introduce new vegetable substances from their 
flora have also met with but little success. 
After the discovery of strychnine and veratrine in the year 
1818, of brucine in 1819, quinine, cinchonine and caffeine in 
1820, coniine in 1827 (1831), aconitine and atropine in 1833, 
Liebig and Wohler, in 1837, recognized in amygdalin the first 
representative of another numerous class of vegetable princi- 
ples, many of which possess energetic physiological properties. 
The chemical investigation of drugs, far superior to the anti- 
quated method of estimation, which was mostly based upon exter- 
nal characteristics, was thus correspondingly forced to the front. 
16. In the mean time, not only the systematic investigation of 
the vegetable kingdom, but also its anatomical and physiological 
study became established more and more upon truly scientific 
principles. In consequence of this advance, the condition of 
pharmacognosy could not remain unchanged. Guibourt (1790- 
1867), in his lectures at the Paris school, and in his writings (see 
p. 5), had already, to some extent, taken a higher standpoint, 
and Pereira (1804-1853), perhaps to a still greater degree, in his 
large text-book (p. 5), in an introductory address in 1842, and, 
furthermore, in his lectures. Schleiden, in 1844, with perfect 
comprehension of the subject, demonstrated the importance of 
the microscopical examination of drugs, which, in 1847, was 
further elucidated in the most brilliant manner by an essay on 
the structure of sarsaparilla, accompanied by microscopic 
figures. When Schleiden’s “Botanische Pharmakognosie,” 
which was written in this spirit, made its appearance in 1857, 
the author no longer stood alone. Weddell, in 1845 and 1848, 
had become acquainted with the Cinchonas in Bolivia and Peru, 
* and in 1849, in his handsome work on this subject, had also 
employed the microscope in an admirable manner for the 
purpose of distinguishing their barks. Schleiden extended this _ 
examination to all the Cinchona barks which at that time oc- — 
