‘ a Alay) are 
He 
70 REPORT OF SCHIMMEL § Co. OCTOBER 1914/ APRIL 1915. 
period of quickest absorption. As soon as the chief constituent of an essential oil, 
for instance eugenol, has been reduced, the hydrogenation generally slackens down at 
once, and this moment can easily be found by entering on a curve, every 15 seconds 
during the process of reduction, the time and the quantity of hydrogen absorbed. As soon 
as the main. reaction is over, the curve shows a sharp bend, and the hydrogen number 
may then be read off direct.from the curve, taking into consideration the temperature 
and the pressure. The apparatus consists of a vessel which serves as a receiver for 
the catalyst (colloidal palladium), the diluting liquid (50 p.c. alcohol) and the substance 
to be tested. By means of an india-rubber tube, the vessel is joined to a U-burette, 
which contains the hydrogen. After the air in the apparatus has been replaced by 
hydrogen, 0,02 g. of dry colloidal palladium is put into the vessel and 50 cc. of 
50 p.c. alcohol added. The vessel is then shaken until no more hydrogen is absorbed. 
Thereafter the substance to be estimated is added, the shaking repeated and the result 
read as soon as the main reaction is over. In this way 4,63 g. of purified technical 
Safrole, in the presence of 0,1 g. of colloidal palladium and 40 cc. of 50 p.c. alcohol, 
absorbed 720 cc. of hydrogen at 22° and 758 mm. pressure, which corresponds 
to 632 cc. at 0° and 760 mm. pressure. Theoretically 641 cc. are required. The 
dihydrosafrole thus obtained boiled between 234,3 and 234,5°. In the same manner 
were reduced: limonene, a kind of artificial sassafras oil (a mixture of 4 parts of safrole 
and 1 part of limonene), genuine sassafras oil, pure anethole, an “artificial aniseed oil” 
(a mixture of 8 g. of anethole and 2 g. of limonene), current clove oil and oil of pimento. 
Albright is trying to simplify his apparatus, so that his method may be put to practical use. 
The results of the experiments are given in the following table: — 
substance ue abe ye ho theoretically 
Satrolie.« (s.../.. “ashi gies i ee 98,3 100,0 
artificial sassafras oil . . . . 111,9 81,1 80,0 
genuine: sassairas-oil «oe 0a 74,8 = 
102,0 74,0 — 
anetholess.... aicies Hak y Beles S 99,6 100,0 
artificial aniseed oil ..% 2+. 4125,1 82,4 80,0 
current aniseedvoil J 2... hc dee) 1258 en 8Z8 t= 
127.3 83,9 = 
current fennel oil; .° ..°..2 (01018 66,8 4 
102,7 67,7 — 
eugenol -ty stints pe eee 98,3 100,0 
artificial ‘cleverail, ..4).. 0 ele 82,8 80,0 
113;3: 828 80,0 
current clove oil >. ->° .. akabald4 83,8 a 
“ 114,0 83,3 = 
current oil of-pimento::... + .. 97,8 71,5 = 
Identification of essential oils in victuals. 
In order to identify essential oils in victuals, patent medicines and liqueurs, 
J. Cerdeiras) determines the behaviour of the oil towards vanillin and hydrochloric 
acid. This reagent is prepared by dissolving 0,5 g. vanillin in a little alcohol, to 
which as much hydrochloric acid (dis0 1,10) is added as is necessary to bring the a 
1) Pharm. Zentralh. 58 (1914), 339. 
