Sixteenth Annual Meeting. 



37 



of naphtha or none in the oil resolves itself into a question as to whether he shall leave 

 it there to enhance the value of the whole, or, taking it out at considerable expense, 

 throw it away and sell the remainder at a less price; for although the higher-priced oil 

 may ultimately cause loss of property or life, it can rarely he traced home to him. Evi- 

 dently the refiner, solely interested on the side of danger, is not he to whom it should 

 be left to decide on the safety of our oil. 



Two dangers arise from the presence of naphtha in kerosene. When a glass lamp 

 falls it often hreaks, and if the oil is adulterated the burning wick, instead of being ex- 

 tinguished, sets tire to the oil as well. This occurrence, however, is rare, and unless the 

 flame extends to the saturated clothing also, is easily controlled. The second danger is 

 thai the naphtha evaporating into the air above shall take fire from the wick, or at 

 the approach of some other flame, and exploding with a violence irresistible inflame and 

 scatter broadcast the underlying oil. Such a fire it is next to impossible to fight. By 

 determining to what temperature any oil can be raised before it will give off explosive 

 vapors, we may judge of the liability of the greater disaster. This is called the "flash 

 test." By learning to what further temperature it must be heated before this explosion 

 or flashing of the rising vapor will become persistent or set fire to the surface of the oil 

 itself, we may discover the chances of the lesser accident. This is called the "burning" 

 or "ignition point," or, properly enough, the "fire test;" but for purposes of confusion or 

 through ignorance, this term is variously applied by dealers to denote either the flashing 

 point, the burning point, or the point at which the oil takes fire spontaneously, a tem- 

 perature practically never reached. Further confusion arises from the fact that different 

 apparatus in use give results varying often by 30°, so that we must know the means of 

 testing, as well as the result, to judge of the oil. The temperature attained in storage or 

 in lamps is commonly stated not to exceed 100 to 110° F. This, however, needs redeter- 

 mination. If that be so, no oil is safe whose ignition point or flashing point is below 

 110°. The former is always higher than the latter, usually but by no means necessarily 

 10° to 30°; so that we cannot assert that oil whose ignition point is as high as 150° is 

 certainly free from danger of explosion, but if the flashing-point be higher than the 

 temperature in the lamp the oil is quite safe. 



Inquiry among our dealers indicates that there are four grades of oil sold or quoted 

 in our market, besides some special brands known by a trade-mark. The poorest is 

 "Standard," warranted 115° fire test, whatever that may mean, and worth at the river 

 about 14 cents per gallon. "150° fire test" is a straw-colored oil, worth one to two cents 

 more. "W. W.," or "Water White," also 150° fire test, costs about 19 cents, and is often 

 sold for "Headlight," which is also white, but 175° fire test, and costs 21 cents. 



The repeated explosion of a lantern led me to examine some of the oils in use by our 

 students. For this I chose Stoddard's apparatus, checking the results constantly by the 

 New York State tester — a modification of the Wisconsin test — first used by the Michigan 

 Board of Health. This gives results about equal to the average of the testers in com- 

 mon use. The following table shows the tests obtained : 



Brand. 



Standard, . . 

 150 test, . . . 

 150 test . . . 

 Water white, 

 Special Brand, 

 Headlight, . . 

 Headlight, . . 

 Headlight, . . 

 Headlight, . . 



Cost 



retail. 



20c. 



25 



25 



25 



30 



30 



30 



30 



30 



Refiners' 

 fire test. 



115° 

 150 

 150 

 150 



150 



175 

 175 

 175 

 175 



Flashing 

 point. 



88. O u 



86.1 



120.5 

 106.2 

 109.2 

 107.8 

 108.8 

 82.1 

 below 50 



Igniting 

 point. 



101.2 



149.9 

 131.7 

 132.0 



128.6 

 134.0 

 102.0 

 81.3 



