444 ODOROnRAPHIA. 



been nutliiiig more than turpentine oil, to which a pine-needle 

 odour has l)een communicated by distillation over coniferous 

 needles, or by an admixture of some true pine-needle oil. A 

 practical examination of genuine pine-needle oil was therefore 

 desiral^le, and, operating upon material of unquestionable origin, 

 Bertram and Walbaum ha^'e determined the physical characters 

 and constituents of several of these oils, so far as the present state 

 of science will allow. The details of the investigation have been 

 published in the " Archives der Pharmacie," 1893, p. 270-305.* 



It has been ascertained that in almost all kinds of pine-needle 

 oils esters of borneol are present, chiefly the acetic ester, and this 

 may be regarded as the body to which the peculiar pine odour is 

 due. The value of the oil is estimated by the quantity of this 

 body present. The particular character of these oils is determined 

 also by the presence of different terpenes. Among these have been 

 found laevopinene, dextropinene, Iccvolimonene, dipentene, phellan- 

 drene and sylvestrene. Most of the oils also contain the sesquiter- 

 pene named by Wallach cadinenc. 



To estimate the value of pine oils, it is necessary, not only to 

 ascertain the specific gravity, the optical rotation and the boiling 

 point.but also to determine the percentage of esters (Bornyl acetate). 

 The quantitative ester-determination may be carried out in the 

 ordinary way by the saponification of the oil with an alcoholic 

 potash lye of known strength and subsequent titration with an 

 acid. The percentage of bornyl acetate is calculated from the 

 quantity of potash in combination. 



The oil of Ahies pedinata, D. C. (A. crcdsa, Lk.) is extracted in 

 Switzerland and the Tyrol from the needles and young shoots of 

 this pine (Xorway Spruce Fir). It has a very agreeable fresh 

 odour, and is therefore largely used as a perfume. The oil has a sp. 

 gr. of 0-875 at 15^ C, and is laevo-rotatory for a column of 100 

 m.m. —20^ 40'. 



Distilled under ordinary pressure, 8 per cent, passes over between 

 150° and 170" C, and 55 per cent, between 170^ and 185°; 

 decomposition then commences, as the l)ornyl acetate present can 

 only be distilled in vacuo or by the aid of steam. 



Naturally, the 1 joiling point of an oil liable to undergo decompo- 



* Aljstracted in Pharni. Journ. [3], xxiii., p. 967 ; and Joiirn. Chem, Soc, 

 Nov., 1893. 



