168 H. G. SMITH. 



gravity and refractive index, and this is noticeable with 

 (e) where the idea was to obtain as much of the eudesmol 

 as possible. With commercially distilled oil from mixed 

 leaves of this species there ought to be obtained a product 

 of a fairly constant nature, and this is more readily seen 

 from the results with (f) and (g). This relative constancy 

 is also illustrated from the results originally obtained in 

 1898 with material from Mooga, N. S. Wales, (over fifty 

 miles from Hill Top), and published in the "Research on 

 the Eucalypts," page 109. The specific gravity of two 

 samples of the oil of this species, distilled at the Techno- 

 logical Museum at that time, but collected on different 

 dates, was 0*915 in both cases; the rotation was a D + 6*14° 

 one case, and + 6*24° in the other; both samples were 

 soluble in one and a quarter volumes 70 per cent, alcohol; 

 the saponification number of one sample was 2*4, and of the 

 other 2*9; the cineol in both, determined by the phosphoric 

 acid method, exceeded 70 per cent. These results, when 

 compared with (f) and (g) above, agree most closely. 



The ester content in the oil of this species appears to be 

 higher in that from the "suckers" than in the oil from 

 seedlings; it is not high in any case, although sufficient, 

 perhaps, to somewhat influence the odour. 



The dextrorotation of the oil of this species is not entirely 

 due to the pinene, because the eudesmol is also optically 

 active in the same direction ; it may be fairly well assumed, 

 however, that the optical activity of the oil gives a good 

 indication of the amount of pinene present. 



From the results so far obtained it may be accepted that 

 the first cutting for oil distillation, with cultivated trees 

 of E. Smithii, should not take place until the seedlings are 

 three years old. The trees might then be expected to 

 furnish a fresh crop of leaves every two years. 



