CONCERNING KEROSENE. 255 



This imperfect combustion produces smoke and imparts to the atmos- 

 phere of the room unpleasant odors, and not infrequently leads to an 

 explosion of the lamp and disastrous conflagrations. The steady flow 

 of the oil through an unencumbered wick keeps the wick burner 

 comparatively cool, and prevents the heating of the lamp and of the 

 oil within it ; but, when the capillarity of the wick is impaired, the 

 burner, lamp and oil within it become heated to a temperature that 

 finally produces a distillation of the lighter portion of the oil, in many 

 instances causing the flame to become dense and smoky ; sometimes 

 streaming above the top of the chimney ; and, if not speedily ex- 

 tinguished, resulting in an explosion and the destruction of the 

 lamp. 



When the normal and cracked oils are mixed, the mixture partakes 

 of the mingled characteristics of the constituents. The mixture may 

 be nearly as good as the normal oils, or nearly as bad as the cracked 

 oils. At the present time the common kerosene sold is either a 

 " cracked" or a "mixed " oil, while the bulk of the high-test kerosene 

 is supposed to consist of " normal " oil ; and, while any or all of these 

 oils may be of any required test, they are of very various quality in 

 other respects. 



The test of an oil, " high " or " low," represents the temperature 

 to which the oil must be heated in order that a suitable quantity 

 usually one half-pint may give off a sufficient amount of inflammable 

 vapor to either flash or burn. The temperatures at which the same oil 

 will flash and burn vary greatly with the character of the oil, being 

 from 10 to 50 apart by Fahrenheit's scale. While it has been repeat- 

 edly demonstrated, by several of the most eminent scientific experts 

 now living, that the temperature at which an oil will burn is of no im- 

 portance as an indication of its safety, this test is still in use in many 

 localities. It is, however, the temperature at which the vapors will 

 flash that is usually understood as the " test " of an oil, and it varies 

 from 70 to 90 Fahr. in low-test oils to 120 to 140 in high-test oils. 

 Experiment has repeatedly demonstrated that an oil that will give off 

 vapors that will flash at 100 Fahr. is safe for any legitimate use. As 

 painful and disastrous accidents are liable to follow the explosion of a 

 lamp, and as the increased danger of explosion where low-test oils are 

 used is obvious to any reflecting person, all efforts to restrict the 

 manufacture or sale of unsafe oils by legislation have been hitherto 

 directed toward the exclusion of very low-test oils from the market. 

 In England such legislation has been based upon very elaborate re- 

 search, and has been in the main successful ; but in the United States 

 no less earnest though less carefully considered measures have been 

 embodied in legislation which has resulted in the enactment of a great 

 variety of statutes giving to some States laws unreasonably exacting, 

 to others wise provisions, while yet others have no legislative restric- 

 tions whatever. Of course, such diverse enactments relating to a 



