21 
bromine used is greater or less. The substance should 
be melted in a flask and the bromine added from 
time to time. 
ANALYSIS OF SUBSTANCE. 
It was obtained pure for analysis by several re-cry- 
stalisations from its solution in alcohol and ether. 
The combustions were made with chromate of lead, 
and with rolls of fine oxydized copper wire in the front 
part of the tube. 
Three out of several analyses are here given. 
I. 
II. 
III. 
0,3324 grm. of substance gave 
1,0591 „ carbonic acid and 
0,3819 „ water. 
0,4314 „ of substance gave 
1,3761 „ carbonic acid and 
0,4980 „ water. 
0,4008 „ of substance gave 
1,2859 „ carbonic acid and 
0,4689 „ water. 
These give the following percentages: 
I. II. III. 
Carbon 86.89 87.00 87.50 
Hydrogen 12.76 12.83 12.99 
The average of the three and the corresponding 
formula are as follows, 
Average. Calculated. 
Carbon 87.13 C 8 87.27 
Hydrogen 12.86 H 7 12.73 
This gives as the empirical formula for this resin 
C 8 H 7 . — The other analyses confirm this result. 
