320 
PIIAKMACEUTICAL MEETING. 
■without any such restriction. It must be rememberedj however, that the 
danger attending the use of these things is well known, and therefore always 
guarded against, whereas not only was petroleum a new article to the public, 
the dangers attending the use of which had to be learned, but, worse still, it 
was introduced as a lamp-oz'/,—an article of unknown and dangerous properties 
was called by the name of an article of known and safe properties. Petroleum, 
infinitely less dangerous in itself, became, by the false colours under Avhich it 
sailed, far more dangerous than gunpowder; that is to say, there was far 
greater chance of accidents occurring by it than by gunpowder. I say that, 
under these circumstances, restrictions on its sale were wisely made, and will be 
wisely retained until the character of petroleum is thoroughly well recognized. 
The Act having been passed, and having come into operation (Oct. 1, 1862), 
merchants, brokers, and other dealers in large quantities of petroleum, became 
commendably anxious to buy and sell only that quality of the refined article 
Avhich should give off no inflammable vapour at temperatures below 100 degrees 
of Fahrenheit’s thermometer. But, unfortunately, an egregiously wrong method 
of determining this point crept into the trade. To ascertain the quality, it was, 
and still is, usual to pour a little of the liquid into a saucer, small bowl, or other 
similar vessel, to apply heat by a lamp, by partially immersing the saucer in 
hot water, or otherwise, stirring the liquid with a thermometer, and applying a 
lighted match from time to time during the gradual rising of temperature until 
the oil caught light. The degree at which this occurred was said to be the 
igniting-point of the petroleum. But disputes as to the igniting-point soon 
occurred. Careful observers frequently noticed that several degrees before the 
petroleum finally ignited, a thin blue flame would seem to shoot from the lighted 
match to the surface of the liquid, or, as one experimentalist described it, “ the 
jpetroleum would appear to ignite ancl go out again,” and some would give this 
as the igniting-point. Other observers, not noticing this flame, or not opera¬ 
ting under the circumstances causing it, found the igniting-point to be much 
higher. But igniting-points were observed and stated which could not be ac¬ 
counted for by this cause of difference. Hence disputes, and hence arbitrations, 
wFich sometimes made the matter worse instead of better. Hence, too, which is 
the most serious part of the matter, much, if not most of the petroleum sent up 
to the present time into retail commerce in the refined state for use by the public 
gives off* inflammable vapour many degrees below 100° F., and is unquestionably 
very dangerous. Slowly, and apparently carefully warmed in the manner al¬ 
ready stated, the petroleum does not fully ignite perhaps till 100° F. is reached, 
and the merchant or broker is satisfied, yet, as I shall presently show, in¬ 
flammable vapour is evolved at perhaps 80° or 85°, and should the inflammation 
of this vapour cause the fracture of a lamp, or otherwise scatter the petroleum, 
danger to life and property ensues. 
The above is only a fair picture of the state of the petroleum trade at the pre¬ 
sent time. My object in writing this paper is to show why the igniting-point 
of petroleum is liable to variation, and also to suggest a modification of the 
usual method by which that igniting-point shall be determined with accuracy 
and constancy of results. And in speaking of igniting-point, I shall hence¬ 
forward always mean the temperature to which the petroleum must be raised 
before its vapour becomes inflammable. This is the point referred to in the 
Petroleum Act, and this is the point at which petroleum becomes dangerous. 
As already indicated the igniting-point of petroleum itself may be several and 
often many (sometimes thirty or forty) degrees higher than the igniting-point 
of the inflammable mixture of vapour and air on its surface, and the petroleum 
does not catch fire for the same reason, doubtless, that gun-cotton may be ig¬ 
nited on a heap of gunpowder without setting fire to the latter; the heat evolved 
is intense enough, but the explosion occurs too quickly for the subjacent ma,- 
