387 



cryptal, when finally separated, gave almost identical results with the previous 

 sample, and are recorded here for purposes of comparison : 



Specific gravity at 20 C. 

 Optical rotation D ... 

 Refractive index at 20 C. 

 Boiling point at 10 m.m. 

 Semicarbazone melted at 



Cryptal from 

 first sample. 



0-9431 



76-02 



98-100 C. 

 176-177 C. 



Cryptal from 

 second sample. 



= 0-9426 

 - 76-20 

 = 1-4830 

 . 99-100 C. 

 176-177 C. 



The oximes and hydrazones were liquid in both cases. 



The molecular refraction calculated for a C IO H I6 O aldehyde with one double 

 bond is 45-82 ; found 45-99. 



The combustion results for cryptal were as follows : 0-1729 gram, gave 

 0-4982 gram. CO 2 , and 0-1638 gram. H 2 O. C. ---- 78-58, and H. --- 10-52 per cent 

 C IO H I6 O requires 78-94 C. and 10-53 H. 



The total amount of aldehydes belonging to this group, extracted from the 

 crude oil of E. hemiphloia, was equal to 10 per cent. 



CRYPTAL FROM THE OIL OF E. POLYBRACTEA. 



The residues obtained on rectifying, for commercial purposes, the oil of this 

 species by steam, were employed for the purpose of determining the aldehydes 

 of this Eucalyptus. The procedure adopted was that described above. A small 

 amount of cuminal containing some aromadendral was isolated. This gave the 

 following constants : Specific gravity at 20 C. ; = 0-9735 ; rotation a D - - 3-6 ; 

 refractive index at 20 = 1-5250. The hydrazone melted at 126-127 C., and 

 the semicarbazone at 210-211. 



The cryptal, when recovered from the neutral sodium sulphite, had a less 

 rotation than that from E. hemiphloia, and gave a semicarbazone which melted 

 at a slightly higher temperature, otherwise the figures were in agreement. To 

 confirm this result, a fresh quantity of cryptal was isolated. The constants for 

 these two samples were as follow : 



The oximes and hydrazones were liquid in both cases. 



Although cryptal can thus be so well isolated, yet methods have not so fai 

 been devised whereby aromadendral and cuminal may be separated from each 

 other in a pure condition; so that the true constants for aromadendral 

 cannot be given with certainty. In the work undertaken for the first edition, 

 the aldehyde was extracted from the oil of E. hemiphloia, distilled in September, 



