423 



If it be considered that the terpene taking part in the construction is 

 camphene, then by a similar arrangement to the above the structure of the mole- 

 cule may be stated as 



CH3 



CH 



HoC 



HoC 



CH 



HC 



CH 



HC 



CH, 



CH, 



CH 



But camphene does not occur in the oil of this plant. There is, however, a very 

 close relationship between the molecule of pinene and that of camphene, and the 

 former may be without much difficulty transformed into the latter. From the 

 above considerations it appears that pinene is the bicyclic terpene agreeing with 

 the constitution of this diterpene, particularly as pinene occurs in the oil in such 

 an exceptionally pure condition. Whether the pinene is derived from the break- 

 ing down of the diterpene, or the diterpene from the combination of the pinene 

 must remain at present an open question. 



The name Phyllocladene is proposed for this diterpene, as indicating the 

 genus from which it has been derived. From its reactions, melting point and 

 analysis, it cannot belong to the paraffin series, and it thus differs from those 

 solid hydrocarbons previously recorded from the essential oils of a few plants. 



The nitrosochloride was readily obtained with the pinene and in abundance, 

 and when purified from chloroform by precipitating with methyl alcohol, it melted 

 at 107-8° C, as did also the similar compound obtained with the pinene from 

 Callitris Drummondi and from those other species of Callitris in which the pinene 

 was a pronounced constituent, but in each case the nitrosopinene prepared from 

 it melted at 132° C. 



Experimental. 



This material was collected at Williamsford, Tasmania, and distilled 30th 

 July, 1908. The yield of oil was only fair, and 524 lb. of leaves with terminal 

 branchlets, gave 18 oz. of oil, equal to 0-215 per cent. The crude oil was of a 

 light lemon-yellow colour, was mobile, and with a very slight aromatic odour, 

 distinctive from that of the " pine-needle oils " generally, but apparently charac- 

 teristic. The oil was very insoluble in alcohol, and it required one volume 

 absolute alcohol to form a clear solution. The specific gravity at 16° C, was 



