— 66 — 
In the meantime A. Hesse^) has now published a more detailed 
study on the same subject, which agrees in the main points with our 
statements. He also obtained from the tuberose extract an essential 
oil in which he detected methyl ester of anthranilic acid and ester of 
benzoic acid, and from lOO grams essential oil he was able to isolate 
not only the ester of anthranilic acid, but also, by oxidising the oil 
with potassium permanganate solution 2), the stable ester of benzoic 
acid. The content of methyl ester of anthranilic acid was 1,13 per cent. 
It was separated by conversion into the difficultly soluble sulphate 
discovered by us^), according to the quantitative estimation - method 
worked out by Hesse and Zeitschel. 
The ester mixture not attacked by potassium permanganate dis- 
tilled from 199° to above 240°; benzoic acid and benzyl alcohol could 
be obtained from it by saponification. A portion of the esters is 
accordingly in any case benzyl benzoate; whether a part of the 
benzoic acid is moreover combined with methyl alcohol, as we suspect, 
is doubted by Hesse, who considers the quantity of the acid in any 
case very small. 
It is all the same a remarkable fact that the ester mixture iso- 
lated by oxidation is, comparatively speaking, readily volatile. Hesse 
gives the boiling point of the first half of the mixture at from 199° 
to above 240^, whilst the other half boils at above 240°. The boiling 
point of benzyl benzoate, however, lies at 324°. According to this, 
lower boiling esters are also present, and the presence of methyl ester 
of benzoic acid (boiling point 199° to 200°) is therefore not excluded. 
Hesse was further able to isolate from the oil, by treatment with 
phthaHc anhydride, an alcohol which according to its boiling point 
206° to 214° and other behaviour must consist chiefly of benzyl 
alcohol. The latter is consequently also present in the free state in 
oil of tuberose blossoms. 
Oil of tuberose blossoms is not only obtained by extraction, but 
also by the enfleurage method. Hesse has ascertained by an 
experiment made on a large scale, that in the enfleurage of 1770 kilos 
tuberose blossoms, 1374 grams essential oil pass over into the fat. 
This essential oil of tuberose blossoms had the following constants: 
d^p^o = 1,012; saponification number 256,3; acid number 32,7. Content 
^) Berichte 36 (IQ03), 1459. 
^) The method applied by us in this case for the first time on oil of tuberose 
blossoms, of separating, by shaking with potassium permanganate solution, the diffi- 
cultly oxidisable substances from those which oxidise more readily, has long been 
known. We have used it also with success, for example, for separating the amyl 
methyl ketone from furfurol in oil of cloves, and also for separating cymol from 
terpene in Ceylon cinnamon oil. See Report April 1897, 50; Journ. f. prakt. 
Chemie II, 66 (1902), 50. 
^) Joiu-n. f. prakt. Chemie 11. 59 (1899), 350. 
