J^IXE-XEEDLE OIL. 445 



sition by heat cannot give any indication of its composition. In 

 this instance, the liljerated acetic acid converts part of the terpene 

 into dipentene, terpinene and polymeric produ3ts, by which the 

 boiling point is raised. A determination of the boiling point serves, 

 however, to distinguish genuine oil from those kinds which consist 

 chiefly of turpentine oil, and therefore distil over completely below 

 170^ C. 



To ascertain the nature of the constituents of this oil, it was 

 heated for some hours with a sufficient quantity of alcoholic potash, 

 and then fractionated bv means of steam : — From the lowest boiliuo- 

 fraction, frequently rectified over sodium, pinene was obtained, 

 boiling at 157^-160*^, optical rotation — 32°. Eefraction for the 

 line Ud 1-4658. For further identification, it was converted into 

 A^ery characteristic nitrosochloride and nitrolbenzylamine com- 

 pounds. 



The fraction l)oiling from 170° to 180° was lavo-rotatory, and 

 when bromated gave a large quantity of limonene tetrabromide, 

 showing the presence of l?evolimonene. 



From the fraction of higherboilingpoint(190°-240°) crystalsweie 

 deposited on cooling, which melted at 206°-207° after recrystalli- 

 sation from petroleum spirit, and had all the characters of 

 h^vo-borneol. The portion boiling above 240° consisted almost 

 entirely of sesquiterpene. The acid separated by saponification 

 consisted chiefly of acetic acid, and the amount of bornyl acetate 

 was found to be 4-r) per cent. 



Operating in a similar manner with samples of other oils, the 

 following results were obtained : — 



The oil produced in Switzerland and in Thuringia from the 

 young cones of Ahies pectinata, D.C. (Abies cxcelsa, Lk.) is also 

 met with in commerce under the name of pine needle oil. It 

 differs from the oil above referred to (from the needles and young- 

 shoots) in its mild odour, low specific gravity and greater rotatory 

 power. The Swiss oil examined by Bertram and Walbaum had a 

 sp. gr. of 0-854, rotation —72°. Between 150° and 170° 16 per 

 cent, distilled over, from 170° to 185° 76 per cent., and the residue 

 amounted to 8 per cent. The amount of ester in this oil was so 

 small* that the separation of borneol was not attempted. The chief 

 constituents are hevo-pinene and hevo-limonene, the latter pre- 



* About 5 per cent. 



