from dry leaves 0.019 % qf alcaloid; 0.008 % ofwhich 

 was quinine, and Moens obtained from Ledgeriana leaves 

 not more than traces. In fresh leaves of C. officinalis 

 Broughton i 1 ) found 0.0035 % of alcaloid; 0.0015 of 

 wkich was quinine, while de Yry found no alcaloid in leaves 

 of C. Calisaya. 



In 1896 de Vry ( 2 ) found in dry leaves of C. C. Ledgeriana 

 sent to him from Java by Mr. van Leersum 0.162 °/ 0 of 

 amorphous alcaloid. Orystalised alcaloids were not found. 



Method. 



The first thing to do was to find a method adapted to 

 our purpose. If possible Uns method should allow the dé- 

 tection of the alcaloid in one half of a leaf. 



Tins requirement is essential for physiological purposes 

 as on] y by such a method it becomes possible to examine 

 thesame leaf at two différent moments. In this way we can 

 obtain a degree of exaetness, which by no otfier means can 

 be reached. Two leaves apparently absolutely the saine can 

 show great différences, while the one is full of alcaloid the 

 other one may be empty. If now one picks the empty 

 leaf in the morning and the full one at night, one would 

 suppose the alcaloid found in the latter to have been for- 

 med during the day, while in fact it was allready présent 

 in the morning. The method employed, an adaptation of the 

 gênerai method for the discovery of the alcaloids, is thus: 



Throughout the investigation the tw T o halves of the same 

 leaf were used. Thèse halves were always longitudinal ones. 

 They were obtained by cutting exactly alorig the midrib 

 of the leaf. In this way the leaf was divided in two une- 

 qual parts one part containing the midrib, the other not. 



(i) Blue book, 1870 p. 238. 



(-) de Vry. Kinologische Studiën, Nederl. Tydschr. v. Pharmacie etc. 

 1896 p. 104 



