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102 REPORT OF SCHIMMEL & Co. OCTOBER 1914/ APRIL 1915, am 
CsA C;H 
Po. eRe CH; 
melts at 150°. On conducting a mixture of carvacrol and ethyl alcohol over thorium 
oxide at a temperature of from 400 to 500°, in addition to small quantities of carvacryl 
ethyl ether, a body is obtained which is perhaps identical with the oily product re- 
sulting from carvacrol. An equimolecular mixture of carvacrol and phenol yields, 
in the presence of thorium oxide and at from 470 to 480°, phenyl carvacryl oxide 
(b. p. 296°) as well as dicarvacryl and dicarvacrylene oxides. A mixture of carvacrol 
and p-cresol, however, produces at from 440 to 450° p-tolyl carvacryl oxide (b. p. 
about 300°) and p-tolyl oxide. At 480°, the catalysis leads exclusively to a mixture 
of p-tolyl oxide and di-p-cresylene oxide. 
place at 480°, dicarvacrylene oxide, C, Ha 7CaHa< As is formed besides. It 
Eugenol. In the same manner as former editions of the German pharmacopoeia 
did for clove oil as well as for eugenol, the Pharmacopoea Austriaca VIII takes into 
consideration an adulteration of eugenol with carbolic acid. It prescribes that 1 g. q 
of the oil ought to be shaken with 20 g. of hot water and 1 drop of ferric chloride 
solution, added to the filtrate obtained after cooling. The liquid may at most 
temporarily colour greenish, but not blue. 
Quite apart from the fact that one is here on the look-out for an adulteration 
which has most likely never occurred yet, the test is liable to lead to an erroneous 
conclusion, as according to our experience with our own preparations, a blue tint of 
the water may result even with pure eugenol and ferric chloride. Recently prepared - 
as well as recently rectified eugenol of older date did not give the reaction immediately 
after the distillation, but already after one day’s standing the water, with which the 
eugenol had been shaken, coloured blue on addition of ferric chloride.. Preparations 
which had been stocked for some time gave bluish tints from the very beginning, 
which must lead the casual observer to the coriclusion that carbolic acid is present. 
In consequence, Austrian pharmacists told us repeatedly that our eugenol had been 
rejected at the official revision, as on account of said test it had been looked upon 
as containing carbolic acid. As it goes without saying that we sell exclusively pure 
eugenol free from any admixtures, and as we convinced ourselves at the same time : 
of the misleading result of the reaction in question, we feel compelled to mention the } 
matter here and to urge its being abandoned. In any case it is evident that it does 
not fulfil the purpose for which it is meant, but on the contrary gives rise to erroneous | 
estimations, so that it is impracticable as a criterion for eugenol and ought not there- 
fore, to be found in any pharmacopoeia. 
As with freshly distilled eugenol ferric chloride does not colour the water blue, 
the reaction depends most likely on oxidation processes, which take place during the 
storage of the oil. 
R. F. Weinland and H. Neff*) succeeded in preparing compounds of eugenol and 
vanillin with iron in the form of a complex anion. They are obtained from alcoholic 
solution of ferric acetate, eugenol, vanillin and alcoholic lye in determined quantities. 
The phenols must be present in considerable excess, so that the alkalis cannot pre- 
cipitate any ferric hydroxide out of the ferric acetate. This large excess of eugenol in 
the preparation of the potassium eugenol-ferrate leads to the co-separation of the 
potassium salt of eugenol. It is then removed by washing with alcohol. Sodium tetra- _ 
1) Arch. der Pharm. 252 (1914), 600. 
