— go — 



four years in succession until they are exhausted ("a mort") and to 

 cut them down to the stump in the fifth. It is estimated that these 

 plots will yield about 6500 cubic metres of timber and about 400 hecto- 

 litres of resin. The trees in the other four plots, estimated at about 

 30000, may only be tapped for four years without killing ("a vie"). 

 A small plan of the site which accompanies the announcement shows 

 the position of the separate plots and the distance of each from the 

 main lines of traffic. 



According to R. A dan 1 ), when examining oil of turpentine for 

 the presence of mineral oil, the old Burton's test is to be preferred 

 to Herzf eld's process 2 ), because the formation of a residue insoluble 

 even in fuming sulphuric acid does not suffice to prove the presence 

 of benzine, inasmuch as the said residue may also owe its existence 

 to the presence of resin spirits. The best way of carrying out Bur- 

 ton's test is by pouring, drop by drop, 100 cc. of the oil into 

 300 cc. of fuming nitric acid, and by weighing or measuring the 

 insoluble residue (which should not exceed 2 °/ ), after washing it out 

 with hot water. Pure resin spirits (di5o 0,8656, n Di50 1,4826), when 

 treated with nitric acid, yielded only 2,1 °/ of residue ( n ni5o 1,455); 

 but when treated with sulphuric acid they yielded as much as 17% 

 (diso 0,8472, n Di5o 1,463). Fractional distillation of the resin spirits 

 resulted as follows: 8°/ of a b. p. from 118 to 150 , 51 °/ of b. p. 150 

 to 180 , 2 7°/ of b. p. from 180 to 220 , io°/ of b. p. 220 to 

 295 ; residue 4°/ . Burton's test is therefore also well suitable for 

 detecting the presence of benzine in resin spirits. If, in addition, 

 the parts which boil over between 120 and 150 are miscible with 

 aniline and acetic anhydride, the absence of benzine is established. 



Wintergreen Oil. Owing to a plentiful output and a some- 

 what diminished sale, the prices have slowly receded, and a sufficiency 

 of oil of sweet birch of reliable quality is available. The production 

 has again increased, both in Pennsylvania and in the more Southern 

 States. The present low price should be an inducement to lay in a 

 sufficient supply, as it is known that during the summer the producers 

 are otherwise occupied, while the increasing consumption tends to put 

 up the prices. 



Oil of Wintergreen leaves. The demand for genuine oil of 

 Gaultheria existing exclusively in the United States has been rather 

 less than in the preceding year and we have therefore been able to 

 supply all the requirements of our customers. 



*) Bull. Soc. Chim. Belgique 22 (1908), 389. Quoted from Chem, ZentralbL 

 1908, II. 1749. 



2 ) Report April 1904, 85 and 86. 



