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and are here, for the sake of brevity, referred to as Ceylon oil mixture 

 and Java oil mixture respectively. 



Ceylon oil mixture: — 



15°/o Citronellal (80 p. c. ; oximation method), 



45°/o Geraniol (99 % Ci H 18 O) and 



40°/° Limonene (distilled over sodium) 



The so-called total geraniol content was 61 p. c. 



Java oil mixture: — 



50°/o Citronellal (80°/o), 



40% Geraniol, 



10% Limonene, 



So-called total geraniol content 92%. 



The following three oils were also examined: — 



Ceylon oil I d 15 o 0,9065; « D — 11° 40'; n D20O 1,48325; 



so-called total geraniol content 61,7%. 

 Ceylon oil II So-called total geraniol content 52,6 %. 

 Java oil . . . d 15 o 0,8848; « D — 4° 50'; n D20 o 1,46559; 



so-called total geraniol content 83,8 % ; 



after 4 weeks d 15 o 0,8902; « D — 4° 40'. 



After oximation we found: — 



Ceylon oil mixture 49,3% Geraniol, therefore 61 —49,3= 1 1,7% Citronellal 

 Java oil mixture . 49,0% „ „ 92 —49,0 = 43,0% 



Ceylon oil I ... 55,2% „ „ 61,7—55,2= 6,5% 



Ceylon oil II ...45,9% „ „ 52,6—45,9=6,7% 



Java oil 37,2% „ „ 83,8—37,2=46,6% 



„ after 4 weeks 40,3 % „ „ 83,8 — 40,3 = 43,5 % 



The results of several estimations resembled each other highly; it was 

 immaterial whether the oximated oil had been acetylated and saponified 

 1 hour or 2 hours; neither did it any longer possess a citronellal odour. 

 Assuming that the preparation used only contained about 80 p. c. citronellal, 

 the mixtures agree well, and the method is serviceable for the determination 

 of citronellal in citronella oil. But is does not reveal the actual geraniol- 

 content of the oil, because other alcohols besides geraniol are present 

 and also enter in reaction during acetylation. 



In this connection we welcomed the occasion to try other testing- 

 methods for purposes of comparison, the more readily so because from 

 another quarter a further method was communicated to us, to which we 

 shall refer in detail later on. 



So far as our present experiments go, the estimation of citronellal 

 in addition to geraniol by formylation (boiling the oil with twice its volume 



