22 
the bottom. At first the temperature should be raised carefully, as the 
mixture frequently foams strongly. The distilling is done in a retort 
which holds up to the mark 400 cc, and it is completed in about 
2 hours. The distillate is then extracted with ether three to four times 
in a separating funnel. The ether extracts are collected together in 
an Erlenmeyer flask, and the ether driven off on a water bath of 
60° to 70°. The further examination takes place in the same manner 
as mentioned above for cinnamon oil. 
Whilst Han us has the intention of testing his method also for the 
determination of vanillin and piperonal, we have made experiments to 
ascertain whether the method is not generally useful for aldehyde and 
ketone-determinations, and we have for this purpose taken in the first 
place citral, citronellal, menthone, and carvone. The results thereby 
obtained were so unsatisfactory, that for the present we have given up 
further experiments. The determination of ketones by Han us' method 
would furthermore not again come under consideration, as their con- 
version with semi-oxamazide proceeds so slowly, that their application 
for quantitative determinations is out of the question. 
For the purpose of distinguishing between cassia oil and Ceylon 
cinnamon oil F. Billon recommends the following reaction: If a few 
drops of the oil to be examined are strongly shaken with a few cc. 
water, the emulsion filtered, and a few drops of a i per cent, solution 
of sodium or potassium arsenite added to the filtrate, the liquid will 
acquire a characteristic green-yellow colour, if the oil is Ceylon cinnamon 
oil; cassia oil is said not to give this reaction. 
When we, however, tried this reaction, we found exactly the reverse 
to be the case. The filtrate of the Ceylon cinnamon oil remains 
completely colourless, whilst the filtrate of cassia oil acquires a faint 
green-yellow colour. This colouration, however, has very little intensity, 
and w^e therefore do not recognise this colour-reaction as a distinguishing 
method between cassia oil and Ceylon cinnamon oil. If it is absolutely 
desired to make use of a colour-reaction as a means of distinction, the 
ferric chloride reaction should decidedly be preferred. This reaction is, 
as is well known, carried out by adding a drop of ferric chloride solution 
to the alcoholic solution of the oils; this produces in Ceylon cinnamon 
oil a green , in cassia oil a brown colour. But we think it desirable 
to dismiss the colour -reactions altogether, as they are not entitled to 
the importance which is often attached to them. Generally speaking, 
the odour and the specific gravity should be sufficient indications whether 
it is a question of cassia oil, or of Ceylon cinnamon oil. 
^) Pharm. Ztg. 49 (1904), 107. 
