On Oil and Oil-gas. 67 
If either new whale oil or old oil that has 
been often heated to 400° or upwards, be 
gradually heated to 500 or 520°, and at any 
period a lighted match be plunged into it, 
the match will be instantly extinguished and 
no!conibustion ensue. | 
A portion of the distilled oil mentioned above 
was’ heated in an open cup to 250° and then 
to 300°. A. lighted match was )presented to 
the surfaceand a slight explosion ensued, oc- . 
casioned no doubt by the otk vapours, but 
when: the match) was plunged into the ail it 
was extinguished. When oil is repeatedly 
distilled it becomes moreand more inflam- 
mable and evaporates ata lower temperature. 
Old oil that had long been exposed to a 
heat of 400°, was taken and put into a di- 
gester, to the amount of a gallon or more. 
The digester was furnished with a small pipe 
to the lid: the oil was heated to 450° with- 
out:any remarkable effect. From thence it 
was gradually raised to 568°. At 526° on 
applying a match to the pipe,:a slight blue 
flame appeared which soon was extinguished. 
From that temperature upwards, desultory 
puffs of inflammable vapour proceeded from 
the pipe, occasioned by the dropping of aque- 
‘ous and oily matter from the lid on the surface 
of the heated fluid; but no permanentgas was 
produced. 
