68 On Oil and Oil-gas. 
A large boiler containing from 50 to 106 
gallons of whale oil, which had been kept at 
the temperature of 400° for 35 days sac- 
cessively was next a subject of experiment, 
It was close, except a small pipe of an inch 
diameter and about 15 feet long elevated — 
from the lid of the boiler. The oit which 
half filled the boiler being at the temperature 
of 400°, a candle was several times apphed 
to the end of the pipe, but no appearance of 
inflammation was observed. A large plug was 
then taken out of the lid and a lighted match 
was applied tothe orifice. No appearance 
of inflammation ensued. ‘The match was then 
plunged into the interior of the boiler, under 
the surface of the hd, and was immediately 
extinguished. I had no opportunity of exa- 
mining the state of the air within, but had 
reason to expect there was a mixture of car- 
bonic acid and common air. 
A glass retort contaming about a pint of 
old oil that had been long heated, was kept 
at the temperature of 600° or upwards for 
an hour or more. The beak of the retort was 
made to terminate in. a wooden box, nearly 
air-tight and containing common air, during 
the whole process. The box was about a 
half a cubic foot in capacity. At the end of 
the time a small opening was made inthe 
