Observations and Experiments on Peruvian Bark. 31 



of dried specimens of the genus cinchona in his possession, 

 collected in 1805, both near Loxa and Santa Fe, he finds 

 many specimens which are not mentioned in the works of 

 any Spanish botanist. 



Dr. Paris, m his valuable Pharmacologia, justly remarks, 

 that notwithstanding the labors of the Spanish botanists, the 

 history of this important genus is still involved in considera- 

 ble perplexity ; and owing to the mixture of the barks of 

 several species, and their importation into Europe under one 

 common name, it is extremely difficult to reconcile the con- 

 tradictory opinions which exist upon this subject. Under 

 the trivial name officinalis, Linn^us confounded no less 

 than four distinct species of cinchona ; and under the same 

 denomination, the British Pharmacopoeias for a long period 

 placed as varieties, the three barks known in the shops : this 

 error indeed is still maintained in the Dublin Pharmacopoeia, 

 but the London and Edinburgh colleges, have at length 

 adopted the arrangement of Mutis, a celebrated botanist 

 who has resided in South America, and held the official situ- 

 ation of director of the importation of bark for nearly ibrty 

 years. 



The apothecaries of this country and England, at the 

 present day, distinguish the denomination of their bark, by 

 terms expressive of the color ; and it is a source of still great- 

 er surprise, to find the orders and prescriptions of some of 

 our most intelligent physicians, designating the species of 

 bark they wish to employ, by no other than one of the terms 

 signifying red, pale or yellow : thus reducing the extensive 

 genus cinchona, of not less than twenty five species into 

 three varieties, and leaving it entirely to the discretion of the 

 apothecary, to give him any species, of a color correspondent 

 to that ordered. Independent of the great insufficiency of 

 these terms to distinguish the numerous species, the color of 

 the powder, is one of the most uncertain and inaccurate 

 methods which could be adopted, of classing or assorting 

 the cinchonas ; as under the same denomination, the best 

 species of bark in commerce, (calisaya arrollenda,) would 

 be confounded with the most inferior, (carthagena,) as the 

 color of the powders of both is yellow ; hence a physician 

 writing for yellow bark, leaves it to the choice of the apothe- 

 cary, to give him what species he may think proper, of a cor- 

 respondent color, but varying in quality from calisaya to 

 carthagena, or in medicinal activity as from 12 to 1. 



