contfi'ined hi Yellow Chidiona. I69 



at their extremitv^ and applied obliquely to each otlier : I 

 propose to call it cinckonutc. of lime. 



I have several times obtained in the crvstallized mass a 

 different disposition; which struck me the more, as it is not 

 often found, namelv, in groups, perfectly round and re- 

 gular in the divergency ot the lamince of which they arc 

 composed. They are in a manner insulated, and each of 

 them exhibits a summit which hangs over the plane surface 

 of the ©thcr crystals. This variation in the assemblage took 

 place only in the tirst crystallizations : I never observed it 

 in those which produced the purified suit. 



The process here indicated is not sufiicicntj as may rea- 

 dily be conceived, to extract from cinchona the whole of 

 the salt it is capable of furnishing. The thick liquor which 

 floated over the first crystallization, and which has been laid 

 aside, still contains a great deal of it. To obtain it, the 

 extractive matter must be freed as much as possible from 

 the other two immediate materials of cinchona which op- 

 pose most the separation of the saline substance, the resin 

 and the mucous matter, which are extracted separately or 

 combined. 



For this purpose, v.hen I w ished to ascertain in the most 

 precise manner the quantity of this salt which yellow cin- 

 chona might contain, confining myself always to water as 

 an agent, I treated, cold, this compound extract, as indi- 

 cated for the purification of the first product, and repeating 

 the dilution, filtration, and evaporation, I found means to 

 insulate, in a manner, the extract of cinchona, which when 

 thus treated retains scarcely any thing but the mucous part. 



When the saline liquor, thus purified, refused to furnish 

 crystals, I united it to that which floated over the salt car- 

 ried to the highest degree of purity, mentioned in the first 

 article of this process. This mixture still furnished me 

 with abundance, and in the last result the liquor I aban- 

 doned had still such a saline appearance as to give me reason 

 to expect something more to add to my recapitulation of its 

 contents. On examination I found nothing but products 

 similar to those which I obtained from the decomposition 

 of the crystallized salt. The matter which I precipitated is 

 absolutely of the same nature ; it is only more coloured in 

 proportion to the resino-extractivc matter it contains. 



The means which I have here described arc attended with 

 considerable embarrassment, and require a good deal of time 

 and expense, which no doubt might be avoided by treating 

 the bark differently. I have several times thought, that by 



employing 



