• — 129 — 



it appears that in the year 1910 30 plants were engaged in the distillation 

 of soft woods, principally yellow pine, together with small quantities of 

 Norway pine and Douglas fir. The plants turned out an aggregate of 

 192442 cords soft wood, as compared with 115310, 99212, and 62349 cords 

 in the years 1909 to 1907 — a proof of the increasing importance of the 

 wood-turpentine industry. 



In view of the large imports of Finnish and Swedish pine-tar oil into 

 France, which are probably due principally to the prohibitive customs 

 duty upon pure turpentine oil, a brief essay by Blarez and Vezes 1 ) on the 

 properties of pine-tar oil from Northern Europe should be very useful to 

 all those in France who are interested in oil of turpentine. In making 

 comparisons between genuine turpentine oil and pine-tar oil, the following 

 general characteristics of the latter chiefly deserve consideration: its 

 very marked empyreumatic, unpleasant odour; its lower sp. gr. (d 25 o 0,8520 

 to 0,8570); its lesser degree of volatility, a property which varies con- 

 siderably in different samples; its higher co-efficient of refraction (n D 1,4700 

 to 1,4800) which also varies in the separate fractions, and, finally, its 

 dextrorotation (« D + 4to+5°). Other points of difference are the rea- 

 diness with which pine-tar oils dissolve in aniline, and Herzfeld's reaction. 

 Mixtures of pine-tar oil with turpentine oil from the Landes may be detected 

 and quantitatively estimated most readily by determining the rotation and 

 by the temperature at which a mixture with known quantities of aniline 

 separates. 



To detect the presence of pine-tar oil in turpentine oil, Herzfeld has 

 recommended the shaking of the latter with an equal volume of solution 

 of sulphurous acid (yellow coloration denotes the presence of pine-tar 

 oil; comp. Report April 1905, 78). Herzfeld has also recommended another 

 test, consisting in pouring the oil under examination over a piece of 

 caustic potash, when the presence of pine-tar oil is revealed by the 

 caustic potash rapidly assuming a brown colour (Report April 1910, 110). 

 H. Wolff 2 ) has modified the last-named test by shaking up 0,5 to 1 cc. 

 potash liquor (d 1,3) with the oil, warming the mixture on the water-bath 

 for 2 to 5 minutes, and then adding 3 cc. water to separate the emulsion. 

 Pine-tar oil causes the aqueous layer to assume a brown colour, turpen- 

 tine gives none, or only a very faint colour. Wolff gives two more tests 

 for pine-tar oil which we quote below, without expressing an opinion on 

 "heir value: — 



1. 5 cc. oil are brought to boiling with 5 drops nitrobenzene, when 

 2 cc. 25% hydrochloric acid are added and the mixture is kept 



x ) Sicr I'essence de pin des pays du Nord de VEurope. Bordeaux 1911. From a reprint 

 kindly sent to us. 



2 ) Farben Ztg. 17 (1911), 21, 78. Quoted from Chem. Ztg. Repert. 36 (1912), 64. 



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