VANILLA, 159 
less and odourless, so that it may be inferred that the whole of the 
vanillin has passed into solution. The united ethereal extracts are 
now distilled from the flask upon a water-bath to 150 or 200 ec. c. 
The residue is placed in a tall narrow stoppered glass, then 200 c. c. 
of a mixture of equal parts of water and a nearly saturated solution 
of acid sodium sulphite added, and the closely-stoppered vessel 
shaken during from 10 to 20 minutes. It is necessary to open the 
flask from time to time, especially at the commencement of the 
shaking, and during the operation to hold the stopper firmly to 
prevent loss of the liquid. 
“ After the yellow-coloured ethereal layer and the almost colour- 
less solution have become sharply defined, they are separated from 
one another by means of a stoppered separating-funnel. The ether 
is returned to the stoppered flask and again well shaken for five or 
ten minutes with 50 c. c. of a concentrated solution of acid sodium 
sulphite and 50 c. c. of water. The aqueous solution is separated 
as before, and placed with the result of the former operation in a 
clean stoppered vessel, This saline solution, which contains all the 
vanillin, is now shaken for a short time with 180 to 200 c. c. of 
pure ether, in order perfectly to remove a small quantity of impu- 
rities derived from the original ethereal extract. After the ether 
has been again separated, the saline solution is poured into a large 
flask with a long, but not too wide, neck, The neck is closed with 
a cork pierced in three places. Through the middle hole passes a 
funnel-tube, reaching nearly to the bottom and dipping into the 
solution. A second tube, equally long, connects the flask with the 
steam apparatus or a vessel of boiling water. The third tube, for 
carrying off the sulphurous acid evolved, passes from the underside 
of the cork to a vessel containing soda-crystals and water. An 
empty wash-bottle should be introduced between this vessel and 
the flask to retain a small quantity of the solution that may be 
carried over from the flask. By using such an apparatus, the 
decomposition of the alkaline acid sulphite can be effected without 
inconvenience from the sulphurous acid evolved. Dilute sulphuric 
acid, in the proportion of 150 c. c. of a mixture of three volumes 
of concentrated sulphuric acid with five volumes of water to each 
100 e. c. of acid sulphite solution, is poured gradually through the 
funnel-tube, and when the consequent evolution of sulphurous acid 
becomes less, steam is introduced to remove it as completely as 
possible, 
** As soon as the wash-bottle becomes much moistened on the 
