the residue dissolved in 100 cc. of hot water: and sufficient ( Rydeaeniont acid 
to render the whole slightly acid. 5D g. of light magnesium oxide and a ce of va 
’ liquids treated as in the case of the free balsamic acids. , oo 
The proportion of cinnamic acid is. determined by the gain in weight on br mi 
The aromatic acids obtained from balsam of tolu are not quite so pure as- ose 4 
from benzoin and storax. The brominated. acids from the two latter are white n 
pleasant-smelling, while those from tolu are slightly brown in colour, and ee 
substance which is extremely pungent and lachrymatory. SS ae 
Balsam of tolu, as a rule, contains very. little that is not soluble in “alcohol, OL 
occasionally samples are met with containing woody matter. ‘Three such. al iple 
contained 1.6, 8.9, and 9.0 per cent. of insoluble matter. HY 4 ee 
Moisture, eeuerally present, was estimated by Diente in < a thin ayer re, 
were found, and the dried balsam was ‘ageltiy quite brittle. aoe 
The determination of the acid value of the balsam is somewhat difficult 
the dark colour, and to the precipitate which is formed on running in. oe 
potash. The authors, therefore, dissolve 5 g. “of the balsam in about 50. ce. 
alcohol, add a large quantity of phenolphthalein- solution — 3 or 4cc. — t 
hot solution with normal alcoholic potash until the colour becomes dane ¥ 
not red), then attach to a reflux condenser, boil up for a few minutes, in order 
up the precipitate, and finish’ the titration. ate 
samples: — 202.2 t0~132:4. Tor acid ee . : ae 
ef 59.3: to, ;.90.9for ester value, >) se ae 
Rs i 154.8 to 206.7 for saponification value, FM 
| : 32.68 to 47.50 per cen. of Ole balsamic: acids. 
m 3) Year Book of Pharmact y, 1914, 355. 
att ae 
