29 
the air pumped out, and then allowed to stand for se¬ 
veral days. The oil on being transferred to the watch 
glass was mixed with air and alcohol, and lost its trans¬ 
parency and clearness. These however returned upon 
its standing for some time. — The mother liquor of this 
oil was treated in the same way. A yellow transparent 
oil was obtained, but in too small a quantity for ana¬ 
lysis. 
Over another portion of fossil resin a stream of 
chlorine gas was passed for two hours. This was then 
dissolved in alcohol and ether as the last. Two oils 
were obtained, neither of which could be crystalised. 
The one which was first precipitated was of a deep 
yellow color and perfectly clear; the other was of a 
dark red color. There was too little of the latter for 
analysis. 
ANALYSIS OF THE CHLORINE AND BROMINE 
COMBINATIONS. 
For determining the amount of chlorine and bromine 
contained in the oils obtained, the combustions were 
made with caustic lime. For determining the amount 
of carbon and hydrogen simply chromate of lead was 
used, having the combustion tube longer than usual. 
Before giving the results obtained, I must remark 
that it is greatly to be regretted that I did not succeed 
in obtaining these combinations in a crystaline form; for 
then there could be no doubt as to their purity. As it 
is, a small portion of this resin may have been held in 
solution by the oils, and so of course have affected the 
