401 



alcohol was not available with which to prepare the calcium salt, but its odour, 

 as well as that of its ethyl ester, was identical with those prepared with the acid 

 of the ester, and also corresponded with similar substances made with pure normal 

 butyric acid. 



The greater portion of the total esters in the oil of E. Perriniana appears 

 to be the low boiling butyl-butyrate ; this is shown from the saponification results 

 with the freshly distilled oil. The saponification number for the crude oil was 

 52-6, representing 13-52 per cent, of an ester having a molecular weight 144. 

 The saponification number for the portion distilling below 190 C. (75 per cent.) 

 was 57-2, representing 14-7 per cent, of ester in this fraction. The ester was not 

 decomposed on direct distillation, as no free acid was detected in the lower boiling 

 fractions. 



It might be well in future analyses of Eucalyptus oils, distilled from trees 

 belonging to this group, to determine the saponification number for the ester in 

 the lower boiling fraction, particularly when the ester value for the crude oil is 

 at all high. 



On the completion of the work on the ester in the oil of E. Perriniana 

 from New South Wales, one naturally returned to the oil of this species 

 previously distilled from Tasmanian trees, the fractions of which had been 

 preserved. The first fraction, representing 18 per cent, of the crude oil, 

 distilling below 173 C., contained a little free acid formed by the natural 

 hydrolysis of a portion of the ester. The saponification number for the ester 

 and free acid in this fraction was 45-8. This result shows the ester in the oil of 

 E. Perriniana of Tasmania to be a low boiling one, and also that the greater 

 portion distilled over in the first fraction, as was the case with the oil of the 

 New South Wales material. 



The Valeric Acid Ester occurring in some 



Eucalyptus Oils. 



IT has been shown (see tabulated list) that esters, either in large or small 

 amounts, occur in all Eucalyptus oils, varying from 60 to 77 per cent, of 

 geranyl acetate, in the oil of E. Macarthuri, to very minute quantities in such 

 oils as E. dives, E. radiata, E. Smithii, &c. The amyl-ester of eudesmic acid 

 occurs in some quantity in the oil of E. aggregata, and in the oil of E. carnea an 

 acetic acid ester has been determined (see under that species). Butyl-butyrate 

 is also a frequent ester in Eucalyptus oils of a certain class. The constituents of 

 these four esters did not, however, explain the presence of a volatile acid 

 resembling valeric acid, which constituent had often been detected in the oils of 

 several species, and in those of E. saligna var. pallidivalvis, E. cinerea, E. gonio- 

 calyx, E. Maideni, E. botryoides, &c., .the presence of a considerable amount of 

 ester 'had been determined. The product of E. saligna var. pallidivalvis appeared 

 to be the best for the determination of this valeric acid ester, because the acid 

 was so well demonstrated, and the amount of ester in the oil comparatively 

 large. 200 c.c. of the oil of this species, collected at Lismore, New South Wales, 

 in May, 1898, were boiled for some hours with aqueous potash, under a reflex 



