28l 



The general characters of the oil of this species are those recorded by us 

 in the first edition cf this work in 1902, under E. amygdalina. The results obtained 

 at that time are reproduced below, and although since that book was published 

 much work has naturally been undertaken with the oil of this species, yet we 

 see no reason why the original statements should be modified, .except perhaps 

 that the cineol content might have been a little higher in all cases. The deter- 

 minations were all made at that time by the phosphoric acid method, when it was 

 considered necessary to press the cake repeatedly until absorption of oil ceased. 

 Cineol determinations as thus made are now kno.wn to give too low results. 



From the record of investigations with the oil of this Eucalypt, now 

 extending over twenty years, it is evident that the general results are practically 

 always in agreement, a fact which again illustrates the comparative constancy of 

 the oil products of identical species. 



The " Peppermint " group appears to be the most recent of the whole 

 Genus, and for that reason might, perhaps, be considered as less stabilised than 

 species belonging to the more ancient groups, yet even with the members of 

 the " Peppermint ' group, a similar constancy is observable. 



Analysis of the Oil. Leaves and terminal branchlets for distillation were 

 obtained from Moss Vale, N.S.W., in March, 1899. The yield of oil was 4-2 per 

 cent. The crude oil was but little coloured, and had a peppermint odour, but 

 this was not so marked as was the case with the oil of E. dives. The secondary 

 odour was aromatic, this being due to alcoholic bodies. A small quantity of 

 eudesmol was detected, as it crystallised after the more volatile constituents had 

 evaporated. Phellandrene was a constant constituent, and the amount present 

 appears to be fairly uniform, but is much less abundant than in the oils of E. dives 

 and E. radiata. Cineol was present to the extent of about 20 to 30 per cent, in the 

 crude oil, but by a method of separation during the primary distillation an oil con- 

 taining 40 to 50 per cent, of cineol can be obtained from this species. Pinene was 

 present, but only in small amount ; the physical and chemical properties for that 

 terpene were, however, secured with the fraction obtained on completely rectifying 

 the first distillate. Free alcohols were present in some quantity, as determined 

 by acetylating the crude oil. The esters were very small in amount, and volatile 

 aldehydes not at all pronounced. 



The crude oil had specific gravity at 15 C. = 0-9026 ; rotation D -- 10-3 ; 

 refractive index at 20 = 1-4703, and was soluble in i volumes 70 per cent, 

 alcohol. The saponification number for the esters and free acid was 3-7. 



On rectification, i per cent, distilled below 173 C. (corr.). Between 

 173-188, 85 per cent, distilled, and between 188-215, 10 per cent, distilled. 

 These fractions gave the following results : 



First fraction, sp. gr. at 15 C. = 0-8987 ; rotation D - - 10-3. 

 Second =0-9111; D -- 9-0. 



The cineol, determined by the phosphoric acid method in the crude oil, 

 was 22 per cent., and in the first fraction, 27 per cent. (O.M.). 



The very high solubility for an oil containing that amount of cineol indicated 

 that alcohols might be present ; a portion of the crude oil was, therefore, acety- 

 lated in the usual way; the "saponification number for this acetylated oil had 

 then increased to 22-4. 



Material of this species for distillation was also obtained from Monga, 

 N.S.W., in July, 1898. The yield of oil at that time of the year was 3 per cent., 

 but as this was the winter it was less abundant in the leaf, although richer in 

 cineol. Similar constituents were present as in the Moss Vale oil, and on 

 rectification the fractions were in agreement with those of the previous sample. 



50068 T 



