409 



On again distilling that portion which came over between 157 and 164 C., 

 the following results were obtained : 



42 per cent, distilled between 157-160 C. = first fraction. 

 35 160-164 C. = second fraction. 



Specific gravity, first fraction, at 15 C. = 0-8660. 

 ,, second fraction ,, = 0-8671. 



Optical rotation, first fraction ,, a D 42-44. 



,, second fraction ,, a D 41-08 . 



The third and final rectification, again taking the first fraction, gave 

 50 per cent, of an oil boiling between 157 and 158 C. This gave results as 

 follows : 



Specific gravity at | C. 0-8755. 

 }i C. = 0-8626. 



Specific rotation taking density at 19 C. = [] 48-63. The refractive 

 index at 20 C. for a specially prepared sample was 1-4660. 



The boiling-point of this lvo-rotatory pinene was thus a shade higher 

 than the dextro-rotatory form; this was shown to be due to the presence of a 

 trace of cineol still remaining, 



The same apparatus was employed for the whole of the distillations, 

 and the results were obtained under exactly similar conditions, and upon a 

 similar quantity of oil. 



From the above results it will be seen that the several fractions of the 

 two oils gave fairly concordant results, with the exception that the oil from 

 E. Icevopinea boiled at a slightly higher temperature than that from E. dextropinea. 

 Another sample was then prepared and the cineol removed by shaking vsith 

 50 per cent, resorcinol ; the remaining pinene boiled at 156 C., the same as 

 that from E. dextropinea. The difference between the Eucalyptus pinenes is 

 in their extreme opposite rotations, and while the specific rotation of the 

 dextro-rotatory form is twice as great as that observed in the pinene from 

 dextro-rotatory oil of turpentine, the specific rotation of the laevo-rotatory 

 form is greater than that of the pinene from laevo-rotatory oil of turpentine. 



The pinene from E. Icevopinea does not, however, show the highest specific 

 rotation to the left. This was given by the pinene from E. phlebophylla ; a 

 sample of the pure pinene from that species having a specific rotation 

 [] D 50-18. This oil was distilled in August, 1919, from material collected 

 at "Braidwood, New South Wales. 



The Eucalyptus pinenes are identical in appearance, being colourless, 

 mobile liquids, and have a similar odour and other resemblances to the pinene 

 from ordinary oil of turpentine ; the odour was, perhaps, more distinctly 

 shown with the dextro-rotatory form. 



The nitrosoehlorides. For the preparation of these compounds one volume 

 of the pinene was added to one of amyl nitrite, and the mixture dissolved 

 in two volumes of glacial acetic acid; this was cooled in a mixture of ice and 

 salt, and concentrated hydrochloric acid and glacial acetic acid, in equal parts, 

 slowly added while the blue colour remained ; it was then allowed to crystallise 

 in the freezing mixture. The crystals from both forms were identical in every 

 respect and melted quite sharply at 103-104 C. The product from the dextro- 

 pinene was heated with alcoholic soda, and the nitrosoterpene thus formed, when 

 crystallised from alcohol, melted at 128-129 C. 



The hydrates. About 4 or 5 volumes of the pinenes were frequently agitated 

 for two or three days with i volume of nitric acid (specific gravity 1-25) and half 

 its quantity of alcohol ; the solutions were then allowed to slowly evaporate in 



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