20 — 
o,i5 to 0,2 gram cinnamon oil is decomposed in anErlenmeyer 
flask of about 250 cc. capacity with 85 cc. water i), and finely divided 
by shaking. Next, about one and a half times the quantity of semi- 
oxamazide^) which has been dissolved in hot water is added; the 
mixture is well shaken for about 5 minutes, and then left standing 
for 24 hours with occasional shaking; especially during the first three 
hours the liquid must be agitated repeatedly. The semi-oxamazone 
separated out in the form of small flakes, is filtered through a Gooch 
tile prepared with asbestos and dried and weighed, and is then washed 
with cold water, and dried at 105° up to the constant weight, which 
operation is completed in 4 to 5 hours. 
The percentage of cinnamic aldehyde is obtained by means of 
the following formula 
a . 60,83 
s 
a — cinnamic aldehyde semi-oxamazone found 
s = quantity of oil used. 
The chemical process which takes place during the conversion may 
be made clear by the following equation 
CONH — NH2 CONH — N = CH — CH = CH — CgH. 
I +C8H7 — CHO = I 
CONH2 CONH, +H2O. 
Hanus proves the usefulness of his method by means of a series 
of analyses, which partly refer to pure cinnamic aldehyde, partly to 
Ceylon cinnamon oils and cassia oils, and further to mixtures of the 
latter with pure cinnamic aldehyde. 
In the case of the cinnamon oils, Hanus gives at the same time 
the results obtained by means of the bisulphite method; in the cassia 
oils they agree well with the values obtained by Hanus' method, but 
in the Ceylon oils they were from 6 to too low. 
We have carefully checked the method in question in our laboratory, 
and on the strength of numerous analyses made by us of commercial 
oils and our own distillates, and also of mixtures of cinnamic aldehyde 
and pinene, we are convinced that this method is very useful for the 
estimation of cinnamic aldehyde : it yields results correct to within 
^) Hanus has proved by experiments that if the proportions here given are 
adhered to, quantitatively correct results v^^ill be obtained; when too much diluted 
he found the figures too low. 
^) With regard to the production of semi-oxamazide , comp. Kerp and 
Unger, Berliner Berichte 30 (1897), 585 and Weddige, Journ. f. prakt. Chemie 
10 (1874), 196. 
We have also found the higher melting point of 223^ to 224° mentioned by 
Hanus for semi-oxamazide, but we are unable to confirm his statement regarding 
the colour (white with pink tinge), as our preparation had a pure white colour. 
