Proceedings of the Polytechnic Association. 753 



temperatures of the atmosphere ignites it, and a continuous flame 

 results. Gasoline is even more sensitive than naphtha, as it ignites 

 at tetnperatares of the coldest da3's of our winters. 



The value of these tests will be readily understood wlien it is 

 remembered that all hydrocarbons in the gaseous form mixed with 

 atmospheric air, in the proportion of seven to twenty per cent, con- 

 stitute an explosive mixture ; and that the fire test properly 

 performed discovers tlie presence of light products in the oil by indi' 

 eating the temperature at which inflammable products in gas form are 

 expelled. And more importance will be attached to it when it is 

 considered tliat twenty per cent of the products resulting from the 

 distilla»tion of petroleum are the light products, which mix with air, 

 at a temperature produced from solar or artificial heat, under nearly 

 all the circumstances^ attending the transportation, storage and use of 

 oil. These light products, in consequence of their volatility and 

 hence danger in the respects mentioned, command a price of only 

 about one-third that of oil which will stand the fire test adopted by 

 the government. 



There is, therefore, an inducement for a questionable class of dealere, 

 if we may use the mildest expression, to remix these cheaper pro- 

 ducts after they have been separated by the refiner and passed the 

 hands of tlie inspector. It is believfed tliat this is too generalTj 

 jDracticed by retailers ; and hence the quite frequent ocenrrence of 

 accidents, as mis-stated and supposed, from petroleum burning oiL 

 In every such case, if a proper investigation is instituted, it will be- 

 found that ignorance, carelessness or fraud has been the cause. 



Ignorance, from the want of a knowledge of the proper qualities of 

 a safe oil ; carelessness, in not exercising that knowledge when pos- 

 sessed ; or fraud on the part of the dealer, who may have secured the 

 confidence of liis customer and thereby been able to impose upon him;- 

 taking the risk of the occurrence of an accident for a small addition 

 to his profits. 



For burning petroleum oil there are a great many lamps of 

 various design, complication and value, all of which, however, par- 

 take, more or less, of the character oi ArgcmcVs, the Annular French, 

 lanij), ParJiers or QnarreVs Sinuhra, the Isu, Carcel, the Solar, 

 Young's Vesta, pLumforcVs and the Fountain lamps of Keir and 

 ParJ:er, which have been in use for burning fat oils during the last 

 fifty to eighty years. Much ingenuity has been exercised in adapting 

 these lamps to the use of petroleum, and with such success that soma 



[Inst.] 48 



