'Carpenter on Cinchona Bark. 363 



Art. XXVI. — Some Experiments and Remarks on several 

 species and varieties of Cinchona Bark. By George VV. 

 Cakpenter. 



Prof. Silliman, 



Dear Sir, 

 In consequence of the late prevailing endemics, ague and 

 intermittent fevers, which have been so universally, felt in al- 

 most every section of our country, in many places to a very 

 alarming and distressing degree, the article Cinchona has in- 

 creased very considerably in practice and demand, and has 

 become one of the most important articles of the materia mcd- 

 ica ; and as the description of the respective species 

 and varieties are so obscure, ambiguous, and confused, 

 that they tend rather to involve the researcher in more dense 

 prolixity than to develop their coccealeu information j and 

 as there is no method so well calculated to ascertain the rel- 

 ative strength of the different species of Peruvian bark as 

 that of analysis, I have thought proper to make trial of the 

 most important species which now occur in our commerce 

 by extracting the alkaline principle upon which its virtue as 

 a medicine depends, and upon the results of which the rela- 

 tive strength may be accurately ascertained. I have also de- 

 scribed these species as they now occur in commerce, which 

 by their external characters may be severally distinguish- 

 ed. If you think the statement of sufficient interest to your 

 readers, I will thank you to insert it in your next Journal. 

 Very respectfully, yours &;c. 



GEORGE W. CARPENTER, 

 No. 294 Market-st. Philadelphia. 



Calisaya Bark. 



Of this very superior species of Peruvian bark, there are 

 two varieties in commerce. 



J 1st. Calisaya arrolenda. 



This variety is in quill from three quarters of an inch to an 

 inch and a half in diameter, and from eight inches to a foot 

 and a half in length. The epidermis is gray and whitisk 



