228 
MINUTES OF PKOCEEDINGS OF 
Rape Oily put up as in first experiment on boiled linseed, resulted, in two trials, 
in the box and cotton being found in ashes within ten hours—the box being put 
up at night, the result was only observed in the morning. In another case I did 
not get the cotton to ignite in six hours; the chamber in the experiment with this 
oil and raw linseed was kept about 170° Fahr. With the five following oils 130° 
Fahr. was the temperature employed. The quantity of waste used was loosely 
packed in a paper box holding about the sixteenth part of a cubic foot. 
Gallipoli Olive Oil .—The two trials made with this oil gave closely similar 
results; in one case rapid combustion was going on in a little more than five, and 
in the other within six hours. 
Castor Oil .—I found the oxidation of this oil to proceed so slowly that only on 
the second day I found the interior of the box to be a mass of charred cotton. 
Its specific gravity (*963) is remarkably high, and its chemical nature very distinct 
from the other vegetable oils I have tried, which, no doubt, has some intimate 
connection with its small heating power. 
I have tried three oils of animal origin with effects very distinct and instructive. 
Lard Oil , an oil of an ordinary specific gravity, viz. *916, produces rapid com¬ 
bustion in 4 hours. Sperm Oily which has a specific gravity of only *882, and is 
not a glyceride, showed its unusual chemical character by refusing to char the 
waste. Seal Oil , which has a strong fish oil odour, not unlike the sperm, but a 
specific gravity of '928, produced rapid ignition in 100 minutes. 
Comparing raw linseed with lard and seal oils, it would appear that the state¬ 
ment is not altogether correct that “ drying oils are more liable to spontaneous 
combustion than non-drying oils.” I have also some reason to believe that the 
rate at which oxidation takes place does not chiefly depend on the presence of 
small quantities of azotized or other easily putrefiable matters, but rather on the 
particular olein, or liquid fat, they contain; however, further inquiry on this point 
is necessary. 
I have made at least two experiments with each oil, and have got remarkably 
uniform results. The ignition of the cotton can be calculated on for any oil with 
about the same certainty as the point at which sulphur or other ordinary com¬ 
bustible material takes fire when heated in the air. So that the term “ spontaneous 
combustion ” may be objected to for the same reason that Gerhardt objects to 
e< spontaneous decomposition ” when produced by oxidation. 
The heavy oils from coal and shale, being chiefly the higher olefines, have a 
remarkable effect in preventing this oxidation, undoubtedly, by giving a certain 
protection from the air. Mixtures of these oils with 20 per cent, rape gave no 
indication of heating whatever at 170° Fahr.; and even seal oil, with its own 
bulk of mineral oil added to it, did not, when placed in the chamber heated to 
135°, reach a temperature sufficient to char the cotton. 
