Notes on scientific research, 147 



for this purpose the preparation of at least one derivative, for instance of the tetra- 

 bromide, would be imperative; to judge from the low rotation it might only be a case 

 of dipentene. 



Besides this, the author reports on the polymerization of «-pinene by treating it 

 with aluminium chloride or other metallic chlorides, whereby polyterpenes are formed, 

 and on addition products of pinene. After heating «-pinene for an hour in benzene 

 with aluminium chloride at 30 to 40°, he obtained a mass resembling colophony. 

 When less time is employed, a diterpene is also formed. If pinene is heated with 

 acetic acid and a-naphthalenesulfonic acid for 3 hours about 30 per cent, of diterpene 

 is the result. The use of formic acid improves the yield. 



The information on addition products of pinene is purely of a theoretical nature. 



Optical rotation of pinene hydrochloride. — According to older data 1 ) the so-called 

 pinene monohydrochloride has certain strange characteristics from an optical point of 

 view, since the hydrochloride prepared from dextrorotary oil of turpentine is said to 

 be inactive, whereas that obtained from laevorotatory oil of turpentine is said to be 

 lasvorotatory. D. E. Tsakalotos and B. Papaconstantinou 2 ) were unable to confirm this 

 unusual phenomenon, on the contrary they obtained from dextrorotatory oil of turpentine 

 a pinene hydrochloride which rotated in the same sense. They worked up the portion 

 of some Greek oil of turpentine boiling from 155 to 156° (760 mm.), which gave the 

 constants [«] D + 45.1 to -f- 47.7° and can be regarded as pure «-pinene. By means 

 of passing dry hydrochloric acid gas through dry pinene, cooled by the help of ice, 

 they obtained a pinene hydrochloride which they purified by recrystallizing from 

 alcohol. The rotatory power was determined in acetone and in alcohol: [«] D + 32.92° 

 at 15° (in acetone) up to +33.43° at 14.5° (in alcohol), on the average +33.19° 

 This d-pinene hydrochloride melts at 127° and boils at 207° (750 mm.). 



The authors also prepared d-pinene hydrochloride in the same fashion: [«] D + 31.31° 

 at 21° in alcoholic solution. Ilts melting point is at 80° and it boils with partial 

 decomposition. 



In order to obtain pure d-camphene, they heated d-pinene hydrochloride with sodium 

 phenolate. Pure d-camphene melted at 42.7° and boiled at 157.6° (745 mm.): [«] D + 83.5° 

 at 25° (10 per cent, solution in alcohol), + 84.05° at 28° (10 per cent, solution in 

 benzene), + 83.8° at 27° (20 per cent, solution in acetone). 



Cymene. — Under the heading "Dyes from waste sulphite liquor" an article was 

 published in the morning edition of the Frankfurter Zeitung, dated April 22 nd , 1917, 

 according to which on the authority of the Papier- Zeitung, Berlin the problem had 

 been solved of producing dyes from sulphite liquor which is a waste product in the 

 manufacture of paper 3 ), with the same facility as this is done in Germany from coal 

 tar. The cymene 4 ) contained in the sulphite liquor was said to be the raw material 

 for making such dyes. It would further be possible in Scandinavia to obtain about 

 300000 kg. of this hydrocarbon from the waste liquor of the paper mills, by means of 

 which, according to a fairly simple process, cotton and woollen goods could by dyed 

 yellow or red, more complicated methods also allowing the manufacture of other 

 coloured dyes. 



*) Comp. Wallach, Terpene und Campher, 2. Aufl., Leipzig 1914, p. 238. — 2 ) Journ. rife Pharm. ei Cfttm. 

 VII. 14 (1916), 97. — 3 ) Concerning the by-products of the manufacture of cellulose according to the sulphite 

 process comp. page 74 of this Report. — *) On the formation of cymene in the sulphite cellulose process 

 comp. Report April 1901, 67. 



10* 



