various Species of Cinchona. 4% 



ouoT deposited a red substance upon the sides of the pan : 

 when reduced to the consistence of a syrup, it still depo- 

 sited, upon cooling, a new quantity of n)atter of a chestnut- 

 brown colour. The filtered liquor was still coloured, and 

 contained the salt proper to cinchonas, which we shall pre- 

 sently describe. 



This brown substance, washed with a small quantity of 

 cold water, is completely soluble in warm water and in al- 

 cohol j it is very little soluble in cold water; its taste is very 

 bitter. 



In the aqueous solution of this deposit, gall-nut'S form an 

 abundant precipitate. Emetic and nitrate of mercury pro- 

 duced the same effects in it as in the infusion. The sulphate 

 of iron is turned green by it. The oxymuriatic acid lose* 

 its smell, and soon forms a flaky precipitate with the solu- 

 tion of this substance. 



Glue produces no more effect than in the infusion : the 

 sulphuric and acetic acids cause no change in it. Diluted 

 with caustic potash, it does not exhale any ammoniacal 

 smell. 



225 grammes of this substance dry, submitted to distil- 

 lation, yielded plenty of water, a sensible quantity of am- 

 monia, and a purple oil, which loses this colour on being 

 dissolved in alcohol, but which resumes it in proportion as 

 its solvent, when exposed to the air, is dissipated. 



It left in the retort 11 decigrammes of charcoal, which 

 on combustion yielded a decigramme of ashes soluble with 

 effervescence in the muriatic acid, and the solution of which 

 furnished lime and iron. 



It is evident, fron) what has been stated, that it is this 

 bitter coloured substance, which, in the maceration of the 

 species lyi cinchona now under consideration, produces with 

 the re-agents all the ph:enomcna we have remarked above. 

 This subbtance seems to hold the middle place, by its nature 

 and properties, between vegetable and animal substances. 

 It is probably the substance which is the ctHcacious principle 

 in the cure f)f intermittent i'cvers. The liquor separat^'d 

 from this sub'^tance wa« treated by alcoliol, wiiieh tool; up 

 tli«- coluuiiu!! p^ut, and it was nolhlngeUe than rj poriioti ot 



tlic 



