various Species of Clnckona. 37 



ITie second species, called red cinchona, and erroneously 

 •■cinchona pitton, is of a deeper colour than the first, generally 

 very thick, not rolled or but litile so, presenting a fibrous and 

 "by no means a resinous fracture, liaving an astringent and 

 slightly bitter taste. 



Lastly, the tbitd species, more recently discovered, and 

 which ought not lo be confounded with the bark of the aii- 

 gustura, as sometimes happens in laboratories, is designated 

 •by the name o( i/elioiu cinchona. 



Its colour is of a pale yellowy its taste is bitterer and less 

 •astringent than that of the two former species ; its fracture 

 is partly ligneous and partly resinous j it is a little more or 

 iess rolled inwardly, according as it is more or less thick. 



Such are the three most common'ly known species of cin- 

 chona, and those most generally employed in medicine; but 

 there are many other species which are confounded with 

 them, the several varieties of wliich are perhaps regarded as 

 different species. These varieties may be occasioned by the 

 age, the soil, the climate, or the parts of the tree from 

 •which the bark has been taken*. 



Alihi^ugh the bark called avgustura is not a true cincho- 

 na ; yet as it has some of the eKterior characters of it, and 

 as it may be easily confounded with it, it is right to make 

 known its distinguishing properties. This bark is yellow, 

 extremely bitter, by no means astringent, and not at all 

 rolled up like the cinchonas. 



§ 11. 

 Are thtire any Characters hy ivhich to distinguish the good 



Species of ■Cinclbonus from such us are lad, or as have been 



adulterated ? 



This is certainly an important object to attain for the suc- 

 cess of this medicine in the treatment of intermittent fevers, 



• M. Mutis distir.;:juishcs seven (Jifl'creut species of cinchona ; but the most 

 ff tKcm arc Dti'known In Franct. The onJy species known at Paris, bcsidei 

 ihotc mentioned above, arc thus denominated : quiixiiiinn nnige ordiiiaite, 

 quinquina gris (unctle, ijuutquina ^ris plal, ijuimiuinn Sanla-l-'e ; but wc are by 

 no means certain that they belonjj; to ditl'erent siK-cies of trees. We shall tec, 

 3, little further on, that several of tliem resemble eacJi olhtr iu almost every 

 point, and tiiat others of theni are not true ciuchonas. 



C s as 



