— II — 
New oxidation - products of anethol and analogous bodies with 
propenyl side -chain are discussed in Joseph Bougault's thesis^). 
If to a I per cent, solution of anethol in 96 per cent, alcohol, an 
excess of mercuric chloride is added, and then gradually a solution 
of about I per cent, iodine, the latter is immediately completely ab- 
sorbed until 2 atoms iodine have been used up with one molecule 
anethol. The first superfluous drop then imparts a yellow colour to 
the liquid. On this Bougault bases a method for the determination 
of anethol and similar bodies with propenyl side-chain. But it can 
only be employed in the absence of bodies with double linkage, phenol- 
or amine-character, as these also react with iodine'^). The determina- 
tion is carried out as follows: To the alcoholic sokition of anethol, 
diluted to about i to 2 per cent., there is added 10 cc of an alcoholic 
solution of mercuric chloride (containing 6 per cent.), after which a 
titrated iodine solution is added drop by drop until the liquid is 
permanently coloured yellow. 254 g iodine correspond to 148 g anethol. 
The reaction^) which occurs in this process, is as follows: iodine 
and mercuric chloride form in the first instance iodine chloride, which, 
under the influence of the water of the alcohol, next splits up into 
hydrochloric acid and hypoiodous acid. The latter then attaches it- 
self to the double linkage of anethol. This view is supported by the 
fact, that the same products are also formed when mercuric oxide 
and iodine are employed : 
H2O + 2 qoHi20 + HgO + 4l = Hgl2 4-2(CioHi20.IOH). 
An excess of mercuric oxide produces a body which shows all 
the properties of an aldehyde, and which possesses the formula 
C^q11^2^2- same body is also formed, when the addition-product 
obtained with mercuric chloride is submitted to further treatment with 
mercuric oxide. The constitution of this aldehyde is expressed by 
the following formula: 
yCUO 
C Ho O — C/^ — C H\ 
for, when oxidised with silver oxide, it passes over into p-methoxy- 
hydratropic acid 
/COjH 
C Hq O — Ha — C H\ 
^) These pour obtenir le grade de docteur, Paris 1902. 
^) Wijs, Zeitschrift fiir angew. Chemie 1898, 291. 
^) For this reason the method is not applicable in practice to the determina- 
tion of anethol contained in essential oils, as it only occurs in combination with 
bodies possessing double linkages, such as terpenes, methyl chavicol. 
