218 Journal of the Asiatic Society of Bengal. [June, 1914. 



shall require for its complete combustion five times its volume 

 of air. Actual experiments show that when oil gas is mixed 

 with an equal volume of air a mixture is obtained which 

 can be used with all types of Bunsen and allied burners and 

 blow pipes such as are used with ordinary coal gas with 

 entirely satisfactory results. 



By regulating the air supply at the burner in the usual 

 way a perfectly colourless flame is obtained which leaves no 

 deposit on crucibles and which can be used for quantitative 

 and blow pipe work in exactly the same manner as coal gas. 



As such a mixture contains only 50% of air and as 

 an explosive mixture must contain over 80%, the margin 

 of safety is ample. 



The calorific value of coal gas is about 600 B. T. units, 

 w r hereas undiluted oil gas has a calorific value of .some 1350 

 B.T. units. A mixture of oil and air in equal volumes will 

 therefore have a calorific value of approximately 

 675 B T. units, i.e. a value about the same as, or rather 

 greater than, that of ordinary coal gas. 



Jt is clear from the above that not only do we obtain a 

 gas far more useful for laboratory and industrial purposes, but 

 that a very considerable saving in expense is involved. It is 

 only necessary to half fill the gas holder with oil gas and to 

 complete the filling by the addition of air. Only half the usual 

 amount of kerosine oil is required and the gas holder is filled 

 in about half the usual time with consequent saving in 

 furnace fuel. Oil gas dilute 1 in this way with an equal volume 

 of air has been in use in the Patna College Laboratory for nearly 

 a year, and not only has it proved to be entirely satisfactory 

 with all types of burner but the expenses in connection with the 



1 3_5 

 2 



as 



i ^ 



Experimental Details. 



Analysis of oil gas. — This was carried out in the usual 



manner 



the fact that it is impossible to estimate the oxygen in a mixture 

 of this gas and air by absorption with phosphorus. The 

 hydrocarbon vapours present (considerable quantities of Benzene 

 were isolated from the tarry distillate) entirely prevent the 

 absorption of oxygen by phosphorus. 



in one experiment phosphorus was actually heated above 

 its melting point in a mixture of oil gas and air containin 

 28% of the latter and the resulting diminution in volume 

 measured only some 02%. 



For the estimation oi oxygen it is necessary to use some 

 other absorbent such as an alkaline solution of pyrogallol. 



Measurement of the rates of propagation of progressive 

 combustion in mixture of oil gas and air : — The gas mixtures 



