35 



is notably the case with C. robusta and with C . verrucosa (both species wdth warted 

 fruits\ and also with species closely allied wdth these. With C. Drummondi, 

 the oil, both from the leaves and from the fruits was similar, and this was also 

 the case with C. calcavata. The dry fruits of those species whose leaves give an 

 oil consisting of geranvl-acetate without borneol, do not contain an essential oil, 

 or, if so, it is present only in a very small amount. This is the case with C. 

 Tasmanica, and with C. rhomboidea . This peculiarity of terpenes with different 

 rotations in the leaves and fruits of the same tree, is of some scientific interest, 

 particularly as this peculiarity does not occur with all the species. It will be 

 noticed that in the results obtained with the material of C. glaiica from Narrandera, 

 the oil from one large tree (kept separate) varied by 6-7 degrees from that obtained 

 from trees growing alongside, and that the ester was also less in amount. The 

 branchlets from the single tree had numerous fruits, and considerably more than 

 were present on the general material. 



(2^ Again, the predominance of a particular limonene, of which the rotation 

 may be either dextro or l^vo, is not constant for all times of the year, so that the 

 rotation of the oil of these species varies in agreement. This is notably the case 

 with C. calcavata and with C. arenosa. The pinenes do not appear to vary in this 

 respect to the same extent as do the limonenes, although it is evident that both 

 forms are present in the oils of most species. Although the rotation of the limo- 

 nenes is thus not constant, yet the other physical characters of the oils are not 

 influenced by the particular activity of the predominant limonene alone ; so that 

 the composition of the oil of each species, when once determined, is found to be 

 always characteristic of it. 



The ester content of the individual oils appears to be far more constant 

 in character, and the indicative value of the cold saponification in following the 

 increase of geranyl-acetate in the several oils, has been most helpful. By this 

 means it was also possible to shaw that the free alcohol in the oil of C. Tasmanica 

 w^as almost entirely geraniol. It is possible that a quantitative value might thus 

 be evolved for some of these esters, if investigations in this direction were under- 

 taken. 



The solubility in alcohol of the crude oils of the Callitris does not appear 

 to be of a very constant nature, because the oils of the group to which C. glauca 

 belongs become much less soluble in alcohol on keeping, and many of them 

 slowly deposit an insoluble resin, w^hich attaches itself to the sides of the bottles 

 in w^hich the oils are stored. Those oils richest in limonene only deposit this resin 

 in very small amount, and those in which the ester of geraniol is present in quantity 

 have not deposited any. The formation of this resinous substance may have 

 some bearing upon the natural preparation of certain of the resin acids found in 

 sandarac, and it is thus e\'ident w'hj^ the sandarac resins from some Callitris species 

 are more soluble in alcohol than are those from other species. 



