34 
TO DISTINGUISH BETWEEN CUMARIN AND VANILLIN. 
As is well known, the cheaper extracts of vanilla contain both vanillin 
and cumarin. Ordinarily these two substances are separated from 
vanilla extracts by TV inton's a modification of the Hess-Prescott method 
and their identity established by difference in the melting point, vanillin 
melting- at 80 G -81- C. and cumarin at 67 : C. Leach 0 has also found 
that vanillin and cumarin when crystallized from ether show differ- 
ences with crossed nicols. vanillin giving marked color, but cumarin 
giving* none. 
Vanillin also gives a more marked color with sodium nitrite and 
sulphanilic acid. but. as pointed out by Leffman and BeamA this reac- 
tion is not characteristic. 
By means of the reagent here recommended for saccharin, it becomes 
a very easy matter to distinguish between these two substances. As 
already pointed out. cumarin yields no coloring matter when heated 
with phenol and sulphuric acid, even at 160° to 170 c C.. whereas 
vanillin yields a beautiful red coloring matter, the reaction taking place 
rapidly at 100 : C., and to some extent even at ordinary temperatures. 
That such is the case mav be seen from the following* observations: 
Minute quantities of cumarin and vanillin, respectively, were mixed 
with small amounts of the reagent and heated for five minutes in a 
bath of boiling water. Under these conditions the cumarin gave a 
colorless melt, whereas the vanillin gave a blood-red one. On adding* 
water and a few drops of 2X sodium hydroxide to the tube containing 
the cumarin no change of color occurred, whereas with water and 
alkali the mixture which originallv contained the vanillin became dark 
purplish red. 
It has been found that other phenols give characteristic color reac- 
tions both with saccharin and vanillin. That such is the case may be 
seen from the following: 
Small amounts of saccharin were mixed with small quantities of the 
phenols named in the table, together with small amounts of sulphuric 
acid, and heated to 160 c to 170 c C. for five minutes. The product 
obtained in each case was then dissolved in water and a few drops of 
2N sodium hydroxide added, with the following results: 
Name of phenol. 
Color with alkali. 
Pvrocatechin 
Hvdroquinone 
Resorcin 
Trikresol e 
Phloroglucin 
Thvmol 
Green. 
Purplish brown, blue fluorescence. 
Salmon pink, strong, greenish-yellow fluorescence. 
Purplish red. 
Wine red. 
Light blue. 
a Jour. Am. Chem. Soc. 1902. 1129. 
b Ibid.. 1899, 257. 
cFood Analysis, Leffman and Beam, 2d ed., p. 324. 
<2 Ibid., p. 324. 
e Trikresol is the trade name of an antiseptic mixture containing the three cresols in nearly equal 
quantities. 
