— 93 — 



taste and the characteristic aroma. The essential oil wich was isolated 

 in the course of the examination, and which was obtained in a yield 

 of 2i°/ , had d 0,8971, and the boiling point 150 to 152 ; when 

 exposed to the air it became dark, and resinified gradually. On 

 fractional distillation, clear limpid first runnings boiling between 120 

 and 150 were obtained; the bulk, of a pleasant odour and somewhat 

 dark, passed over between 151 to 15 5 ; a small quantity of brown 

 last runnings boiled from 155 to 190 . 



The high prices of American turpentine oil have directed attention 

 to cheaper kinds of oil of turpentine. To the latter belongs the 

 Finnish pine tar oil, the price of which is about half that of the 

 American oil. But as its pungent odour and also its yellow colour 

 render its use for the brighter paints objectionable, O. Aschan 1 ) 

 has attempted to determine the impurities which are the cause of 

 these faults, and to find means by which they may be removed. 

 Finnish pine tar oil is obtained as a by-product in the preparation 

 of wood-tar from conifers. It is separated from the tar-water on 

 which it floats, and once more distilled with the addition of lime. 

 The crude material for the tar- distillation consists of the stumps of 

 the felled pines and firs, which are available in large quantities in 

 the interior of Finland. 



Aschan examined an oil with a pungent odour, which passed 

 over first when the crude turpentine oil was distilled with steam. 

 On fractional distillation it boiled between 28 and 160 . The 

 portions boiling below 40 had an aldehyde-like odour, which from 

 6 5 upwards became suffocating like quinone. From this point the 

 colour of all the fractions was green-yellow to orange-yellow, and this 

 colour could not be removed even by repeated distillation. A more 

 detailed examination showed that diacetyl and its homologues produce 

 both the pungent odour and the coloration. All fractions were 

 unsaturated, and gave an aldehyde reaction. In the fractions boiling 

 below 40 , furane was detected, and in those boiling between 60 

 and 70 , a-methyl furane, the latter in large quantity. In the fractions 

 of the boiling point 90 to ioo°, methyl isobutyrate was present. 

 Benzene and its homologues were also detected. 



For the purification of Finnish pine tar oil the following come 

 under consideration: 1. dilute caustic soda lye, which condenses diacetyl 

 and its homologues to quinones of the benzene series, and thus 

 easily removes them, and which also destroys the offensive impurities of 

 which small quantities are present in the first runnings. 2. Sulphuric 

 acid, which in moderate concentration resinifies furane, the aldehydes, 



*) Farmaceutisk Notisblad 1907, 93; accord, to Apoth. Ztg. 22 (1907), 483. 



