90 Proceedings of the Royal Irish Academy. 



the Oregon Douglas Fir pinene is not present, and the bornyl acetate is 

 much less in percentage. The peculiar fragrance is chiefly due to the 

 presence of the highly odoriferous substance geraniol, slightly modified 

 by the small amount of bornyl acetate pi-esent " 



Two previous analyses of the leaves of Douglas Fir are on record : — 



Brandel and Sweet* examined foliage of Or^on Douglas Fir collected in 

 Washington State, and found a yield of 0-8 to 1 per cent, of oil ; no pinene 

 present, the main constituents being terpencc, of whidi the principal fraction, 

 boiling at 161" to 169°, contained camphene. A small fraction, boiling at 

 175° to 176°, was thought to be limonene. The higher boiling fraction 

 contained bornyl acetate. 



This analysis a'jrees with English-grown Oregon Douglas Fir in the 

 absence of pinene and in the small quantity of bornyl acetate present. 



Schorger* made an analysis of foliage of Douglas Fir, gathered in the 

 southern part of the Sierra Nevada, California, which yielded on distilla- 

 tion 0-1 6"l per cent of oil, with specific gravity of 0'873 to 0876, optical 

 rotation of -17'^ to -22^ and containing: — 



a-pmcne. .... 



■ib per 



j3-pinene. .... 



48 



limonene, .... 



6 



bornyl acetate. 



6-1 



bomeol, .... 



6-5 



unidentified green oil, 



.1 



loss, 



5 



This analysis would indicate an oil agreeing with Colorado Douglas Fir 

 in the presence of pinene : but in contains much less of the higher boiling 

 esters. 



It is evident that further investigation is required on the odours and oils 

 of the different species and varieties of Douglas Fir in America. 



It is worthy of note in this connexion that the difTerent forms of the 

 Yellow Pine in western North America, which closely resemble the various 

 Douglas Firs in their distribution, yield each, on tapping their stems, an 

 oleo-resin, which contains a different oil.' Typical Finns ponderosa, with 

 moderate-sized cones occurring in the same region as the Oregon Douglas 



' thtji imicKutUal Rcrieir (Milwaukee), Nov. 1908. p. 326. 



» Jotin,. Jmtr. 0>€m. Sk., ixxv. p. 1895 (1913). 



5 \. W. Schorger, in Prue. Soc Amer. PorttUrt, xi. 32-39 (1910). 



