ON VARIOUS SPECIES OF CINCHONA. £ K> 



in acids with effervescence, and is nothing but a mixture <• 

 carbonate of time and charcoal. 



0« Its solution does not alter the colour of litmus. In al- 

 cohol it is completely insoluble. 



0. The fixed alkalis, whether caustic or carbonated, de- 

 compose it. and precipitate lime from it, either pure or in 

 the state of carbonate. 



7. It is not decomposed by ammonia ; which proves, that 

 its acid has a stronger affinity for lime. 



8. Both sulphuric and oxalic acids form a precipitate in its 

 solution, if it be in a tolerably concentrated state ; the result 

 being sulphate or oxalate of lime. 



9. It produces no apparent alteration in solution of ace- 

 tate of lead, or of nitrate of silver. 



10. Concentrated sulphuric acid, poured on this salt re- 

 duced to powder, blackens it slightly; but it does not emit 

 any of the pungent vapour evolved from acetates. 



11. A remarkable circumstance is, that the infusion of 

 tan, and of some species of cinchoua, that of Santa Fe for 

 instance, occasions a yeiiow flocculent precipitate in the so- 

 lution of this salt. 



The various phenomena produced by these experiments \ compound 



indicating, that this salt consisted of a vegetable acid and oflime aud 

 _. ■ , 111 -i some acid. 



lime, in order to decompose it, and obtain the acid separate, 



I employed oxalic acid, which is well known to render lime 

 most insoluble by combining with it. With this view I pro- 

 ceeded in the following manner. 



I dissolved 100 parts of this salt in as much water as was Analysis of it. 

 requisite. Into this solution I poured a solution of oxalic 

 acid, from a quantity of a known weight, at different t;nes, 

 till no precipitate was formed. About twenty-two parts were 

 necessary, to precipitate the whole of tiie lime, yet I obtained 

 but twenty-seven parts of dry precipitate. 



This proves, that the oxaiic acid employed retained about 

 half its weight of water of crystallization; and that the salt 

 of cinchona contained but a small quantity of lime, lor in 

 twenty-seven parts of oxalate of lime there are but fifteen of 

 this earth at most. 



After having thus separated the lime from this salt by 

 means of oxalic acid, I allowed the supernatant liquor to 



evaporate 



