368 



Free acetic acid always occurs in the oils of this species, and phenols are 

 also present, so that the crude oil is usually red in colour, particularly if the digester 

 and worm of the still had been constructed of iron. 



Determination of the Ester. The ester was determined by heating on the 

 water bath, under reflex condenser, with 20 c.c. semi-normal alcoholic potash, 

 and titrating with semi-normal sulphuric acid in the usual way. The following 

 figures give the .results obtained with an oil containing the least amount of 

 ester we have so far experienced with the oil of this species : 



2-9725 gram, required 0-5124 gram. KOH . . S.N. = 172-38. 

 3-0125 0-5194 ,, ' 172-40. 



As the ester was wholly geranyl-ace-tate, with a molecular weight 196, the 

 percentage of ester was 60-34. 



To determine the free acid a portion of the oil was agitated with dilute 

 aqueous sodium hydrate, washed and dried. 



1-945 gram, neutral oil required 0-3332 gram. KOH .;. S.N. = : 171-3. 



The result from this is 59-95 per cent, of ester, and free acid showing a 

 saponification number i-i, or an ester value of 0-39 per cent. It is not permissible 

 to attempt the determination of the free acid by alcoholic potash in the usual way, 

 as the saponification of the ester commences at once, and with two hours' contact 

 the whole is saponified. This is shown by the following result obtained with the 

 neutral oil as above. 



In this case only one and a half hours elapsed after the addition of the 

 alcoholic potash before titration. 



1-65 gram, required 0-2828 gram, potash .-. S.N. = 171-4. 



This result is equal to 59-99 per cent., and shows that the ester was entirely 

 saponified during that time. 



The Free Alcohol.' The acetylation of the free alcohol in the above sample 

 was carried out in the usual manner, by boiling for one hour and a half with 

 acetic anhydride and anhydrous sodium acetate, adding water, and finally washing 

 until the oil was neutral. By cold saponification with two hours' contact : 

 1-5066 gram, required 0-3164 gram. KOH .-. S.N. : 210. 



This gives an ester value of 73-5, calculated as geranyl-acetate. As 59-99 

 per cent, of ester was originally present, this represents 13-51 per cent, of ester 

 formed by the free geraniol present. The free geraniol in the oil was thus 10-6 

 per cent, and the ratio -^^i"' 01 == 81-100. 



Corresponding duplicate determinations were obtained in each case. 



It thus appears that other esters found in Eucalyptus oils were practically 

 absent in that of this species, and all our results support this conclusion. At 

 any rate, they can only occur in very small quantity at any time. 



The Geraniol. The pure alcohol was prepared by saponifying the oil in the 

 cold and then combining it with dry calcium chloride. The compound C IO H I8 O, 

 CaCl 2 was then ground up with benzene, freed from liquid by means of the 

 pump, and finally washed with dry ether. It was then decomposed by water, the 

 oil washed, and finally steam-distilled. 



The resulting product was colourless, had a rose-like odour, was inactive, 

 had specific gravity 0-885, and boiled at 224-225 C. (uncorr.). 



A portion was oxidised by using potassium bichromate and sulphuric acid 

 in the usual way and the product combined with sodium bisulphite, the crystalline 

 mass purified and decomposed. The separated oil had an odour of citral and 

 formed the citryl-/S-naphthocinchoninic acid melting at 199-200 C. 



The Acid of the Ester. The aqueous portions remaining from the saponi- 

 fications were mixed together, the whole evaporated almost to dry ness, and 

 distilled with dilute sulphuric acid, adding fresh quantities of water until the 



