27 



tities causing the appearence of a precipitate. It was con- 

 sequently decided to use a less excessively sensitive reagent, 

 yet a more ttian sufficient sensitive one, viz. caustic potaslï 

 and to consider a leaf, whieh on application of tins KOH 

 gave no precipitate to be empty, one which gave one as 

 to be „full u . Using tins reagent one can estimate quan- 

 tifies to a certain degree f. e. traces, very little, but little, 

 pretty much, much, very much and an exceedingly large 

 quantity, but to be safe, only those leaves were used for 

 the experitnents as to the formation of alcaloid, which ga- 

 ve no reaction with KOH. 



Several preliminary experiments had taught me tliat the 

 two halves of a leaf, examined at the same moment ga- 

 ve corresponding resnlts. As an example, I can state the 

 results obtained with leaf- halves, from which I did not pre.- 

 viously know which two belonged together. 



1 lin 11 • x i f vo 1 [but little 

 o j halves belongmg to leaf N . 1. — j 



3 ( o _ I pretty much 



5 A l » « » » I 



4 f l » » 



5 | o _ I vei T much 



7 ( . J traces 



8 I " " " " l traces 



9 | - _ j empty 



10 j " " ; ' " l „ 



Yet thèse discriminations were not used, as allready 

 stated above. 



In the statcments below the expression „ empty" mëans 

 that the chlorofonn résidu dissolved in water acidulated 

 with HC1 gave no precipitate with KOH, while „full" 

 means that KOH caused a considérable precipitate. 



It was necessary to first inquire into the quantity of 

 alcaloid présent in the leaves of Cinchona. 



