CASSIA. 215 
are added, and the whole, with frequent shaking, is warmed in a 
water-bath until the combination of aldehyde with the bisulphite 
of sodium is entirely dissolved and the non-aldehydes, as an oily 
layer, float on the solution of the aldehyde salt. It is now 
allowed to cool, is shaken up twice with ether, first with about 
200 c. em. and then with 100 c.cm. The ethereal extracts of 
non-aldehydes are separated off, brought together and filtered 
into a good-sized beaker previously weighed, in which is placed 
a spiral-shaped platinum wire. The ether is evaporated as 
quickly as possible, by putting the beaker in hot water. As 
soon as the liquid ceases to foam up when moved around, 
it is allowed to cool and is weighed. Then the beaker is again 
placed in the water-bath for 10 minutes, weighed again after 
cooling, and so on until the difference between two weighings is 
not more than 0°3 gram. The last but one is then taken as the 
correct weight. (The method of expelling the ether has a great 
influence upon the accuracy of the result. The non-aldehydes 
can be volatilized, but not easily. The ether must therefore be 
boiled rapidly and the beaker must not be allowed to stand in the 
water-bath any longer than is necessary for the evaporation of 
the ether.) The weight of non-aldehydes thus obtained being sub- 
tracted from that of the cassia oil used, the remainder gives the 
amount of cinnamaldehyde. 
“ Example.—Oil used, 79°71 grams. 
Ist weight of glass, after expulsion of the ether, 147°55 grams. 
2nd 39 2 3) 146°84 PP) 
3rd 3 98 pA 146:58  ,, 
From 146°84 
Deduct 128°34 Tare. 
Non-aldehydes in the oil 18°50 grams, or 23:1 per cent. 
Therefore 100 less 23-1 = 76:9 per cent. of cinnamaldehyde. 
“ By repeating the experiment upon a second portion, the variation 
in result (if the directions are closely followed) generally amounts 
to a few tenths of 1 per cent., rarely to 1 per cent., which in 
practice is more than sufficient. 
“The other constituents of cassia oil, including eventual adul- 
terations (resin, petroleum, fatty oil, etc.), are not affected by the 
