Scientific and other notes on essential oils. 67 



of Scotch firs, and in point of fact suggests that this procedure is to be combined 

 with the manufacture of cellulose from wood 1 ). If such wood is boiled with caustic 

 soda under pressure, turpentine might be blown off with steam towards the end of the 

 process and in the liquor the rosin dissolved will be found, besides obtaining the 

 cellulose of the wood 2 ). 



Besemfelder 3 ) rejoins that he made no pretensions to free the whole supply of 

 coniferous wood from resin, he laid special stress on the fact that the quantity of 

 extract produced, rose and fell with the amount of the wood surface introduced into 

 the drying apparatus. 



Besides this, according to Schwalbe's calculations, not 8000 but 4000 boilers would 

 be necessary for the rapid-maturing wood process. 



Besemfelder thinks, however, that Schwalbe's assertions prove that by utilizing 

 the various sources of resin, especially by tapping our coniferous trees, it will be 

 possible to cover the German demand for turpentine products. 



For obtaining turpentine by tapping, H. Wislicenus' 4 ) process, which we already 

 reviewed in our last October Report, seems to be the most practical. To judge from 

 an article 5 ) of his on turpentine production from Scotch firs by means of open and 

 of closed tree lesions, others seem to prefer the old incision method. 



As Wislicenus remarks, it is of vital importance in Germany's present condition 

 to obtain the gross demand for turpentine oil and good resin from her own forests. 

 Whereas on the one hand it was possible to obtain easily sufficient less valuable 

 gutter and scrape resin, very poor in oil of turpentine, according to the cheap and 

 simple blazing method, as practiced in the Saxon Yogtland from time immemorial, 

 which is now being utilized again, the problem had hitherto not been solved of 

 producing good oil of turpentine in sufficient quantities as well as colophony of a 

 quality such as the resin-working and nearly always resin-distilling industry demands. 

 The value of the crude resin diminishes considerably according to the length of time 

 the crusts of resin are formed on the trees owing to the oxidizing effect of the air. 

 The so-called "wild resin", being mostly old and brittle, which had to be collected in 

 1915 from the abrasions, produced by deer on pines, was positively refused by the 

 resin-working industry owing to its having become unsuitable for distillation purposes 

 from the effect of the air and from admixture with impurities of all kinds. When open 

 incisions are made, the value of the resin diminishes very quickly; but where the bottle 

 system is employed, a product of very great value is obtained. A sample of turpen- 

 tine of this kind distinguished itself on examination in our laboratory by its very light 

 colour and the total absence of mechanical impurities most favourably from the ordinary 

 commercial products. On being distilled with steam, 32 per cent, of oil of turpentine 

 were obtained. After remelting the residue, a light yellow colophony was produced 

 whose most promising quality is apparently its light colour and which accordingly 

 would be more suitable for some purposes than the ordinary more or less brown 

 commercial product. The physical and chemical qualities of the oil proved it to consist 

 of a-pinene in the main. It is characterized by a mild, pleasant smell and can compete 

 in every way with the very best trade samples. 



x ) Comp. Schwalbes article Harz und Terpentin aus deutschem Walde {Zeitschr. f. Forst- rind Jagdwesen 

 48 [1916], 99). In this article the author expresses the opinion that at present it cannot be foreseen if and to 

 what extent a German rosin and turpentine industry, dependent on the resin-tapping, 8jc, of the living Scotch 

 pine, can the founded with paying results in times of peace. — 2 ) In this article the terms turpentine and 

 oil of turpentine are confounded! Comp. p. 78, foot-note 1. — 3 ) Chem. Ztg. 41 (1917), 258. — 4 ) Chem. 

 Ztg. 40 (1916), 559; Report October 1916, 53. — B ) Forstliche Wochenschrift Silva 1917, N° 11. 



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