214 



Plnene. — It is also very probable that dextro-pinene is 

 present in small quantities, as 7 per cent, of the oil distils 

 below 175 '5° C, and by shaking out with resorcinol solution^ 

 a small amount of dextro-rotatory body was obtained, with 

 an odour characteristic of pinene. Attempts to separate the 

 characteristic nitrosochloride were not suc€essful, but this 

 does not prove the absence of pinene, as it is very difficult 

 to prepare the nitrosochloride from a high-rotation pinene. 



D. Aldehydes. 



Esfiination. — The total amount of aldehydes occurring 

 in the crude oil was estimated by shaking 20 ccs. of the oil 

 in a cassia flask with about 150 ccs. of a 35 per cent, sodium 

 bisulphite solution and lieating on a water bath for three 

 hours. The unabsorbed oil was brought into the neck of the 

 flask by the addition of more bisulphite solution and the 

 volume read off when cold. By this method, a figure of 

 7 '5 per cent, of aldehydes was obtained. An identical value 

 was also obtained on a sample of oil distilled in May of the 

 following year. This would indicate that the aldehyde con- 

 tent does not vary appreciably with the season. 



Sejjaration of the Aldehydes from the Oil. — It was found 

 that the oil contains more than one aldehyde, and they were 

 first separated from the higher boiling fractions of the oil 

 by shaking the fraction with twice its volume of sodium 

 bisulphite solution (35 per cent.). By this method, a large 

 quantity of bisulphite addition compound was precipitated, 

 which was filtered on the Buchner funnel. The filtrate con- 

 sisted of oil and aqueous liquor, and these were separated^ 

 and the aqueous portion used to wash the solid residue in 

 the funnel. This washing was continued until no more oil 

 appeared in the filtrate. The residue was then washed with 

 fresh sodium bisulphite solution, followed by a washing with 

 alcohol-ether mixture. The solid cake was dried, decomposed 

 with hot sodium carbonate solution, and the aldehyde 

 separated. This aldehyde is here referred to as aldehyde A.(i) 

 On treating the liquor separated from aldehyde A (containing 

 sodium bisulphite, sodium carbonate, etc.) with caustic soda 

 solution, a further separation of aldehyde took place. This 

 aldehyde, called aldehyde B, was extract-ed with benzene, 

 which was later evaporated off. The aqueous portion of the 

 filtrate from the separation of the solid residue was treated 

 with hot sodium carbonate solution, but no separation of 

 aldehyde occurred. On the addition of caustic soda solution, 



(1) The aldehydes separated are here indicated by the letters 

 A, B, and C, as it is later shown that they are mixtures. 



