Observations and Experiments on Peruvian Bark. 33 



2nd. Calisaya Plancha, (Flat Calisaya.) This variety con- 

 sists of flat, thick, woody pieces, of a reddish brown colour, 

 deprived of its epidermis, and the interior layer more fibrous 

 than that in the quill. This variety yields from twenty to 

 twenty-five per cent less quinine than the arrollenda, and is 

 consequently a less desirable article. 



Superior Loxa or Crown Bark. 



Loxa is the name of the province and port, where this 

 bark is obtained and from which it is exported. In this 

 province cinchona was originally discovered. This bark 

 has been highly esteemed by the royal family, and is that 

 which has been selected for their use ; hence, the name of 

 Crown Bark. The following are the characters which dis- 

 tinguish this bark. 



The Loxa bark occurs in small quills, the longitudinal 

 edges folding in upon themselves forming a tube about the 

 circumference of a goose quill, and from half a foot to a foot 

 and a half in length. It is of a greyish colour on the ex- 

 terior, and covered with small transverse fissures or cracks, 

 the interior surface is smooth and in fresh or good bark of a 

 bright orange red, it is of a compact texture and breaks with 

 a short clear fracture, it is the bark of the cinchona conda- 

 minia and is known at Loxa by the name of cascarilla fina. 

 Yet, notwithstanding this bark appears to have held the de- 

 cided preference to all other species, analysis fully indicates 

 that it is not equal in medicinal strength by at least twenty- 

 five per cent, to that denominated Calisaya; this bark is more 

 astringent and less bitter than the calisaya. 



This species yields from twenty-five to thirty per cent, less 

 cinchonine and quinine, than the caylisaya arrollenda does 

 quinine, and the proportion of cinchonine is much greater 

 than that of the quinine. 



Cinchona Ohlongifolia or Red Bark. 



The above term appears to be more applicable to the spe- 

 cies in question, than any other which can be selected, as 

 under that denomination the best red bark has always be,en 

 well known, and as there is but one other species aflfbrding 

 a red powder, it is not likely to be confounded. The infe- 

 rior red bark of which there is a considerable quantity in our 



Vol. XVI.— No. 1. 5 



