THE NEW YORK JOURNAL OF PHARMACY 



9 



whole, the Texas and CaHfornia pro- 

 ducts having somewhat less. About 60 

 to 65 per cent, of Pennsylvania oil is 

 kerosene or burning oil under one name 

 or another, which constitutes the next 

 group of distillates. 



A temperature of from 350° F. up- 

 wards is required for production, and the 

 flash-points vary from 100° to 250° F. 

 The flash-points I have given are only 

 rough approximations, for they vary 

 with the different crude oils and in dif- 

 ferent refineries and are trade secrets 

 of the oil refining business. There is, 

 however, a marked difiference between 

 the temperatures at which the gasoline 

 and kerosene group vaporize, so that an 

 entirely dififerent treatment is necessary 

 for each, to provide proper vaporization. 

 In gasoline practice, no special provision 

 is necessary. A stream of air at atmos- 

 phere temperature breaks up the liquid, 

 the eddies of air current through the 

 manifolds and valves break it uj) still 

 more, and the heat of the motor and that 

 caused by the compression of the 

 charge makes the fuel vaporize sufficient- 

 ly for practical purposes. If properly 

 vaporized, one hydro-carbon compound 

 is as good a fuel as another, generally 

 speaking. There is not much chemical 

 difiference between gasoline and kero- 

 sene, and the proportions of carbon, hy- 

 drogen and oxygen are approximately 

 the same. The considerable difference 

 in volatility or vaporizing ability, how- 

 ever, has bothered many an ambitious 

 designer. Much more heat than that 

 supplied by the atmosphere is necessary, 

 and it must be furnished at the proper 

 time. Kerosene has an unpleasant habit 

 of disassociation when subjected to high 

 temperatures. That is, its compounds 

 break U]) into other compounds, leav- 



ing a residue of free carbon or soot 

 This is particularly true, when the heat- 

 ing takes place when the supply of oxy- 

 gen is insufficient for combustion. 



Many devices have been tried along 

 the line of gasoline appliances, such as 

 hot air supply to the carburetor, heated 

 retorts in wliich the fuel was vaporized 

 before being mixed with air, etc.. and 

 several successful ones are on the mar- 

 ket. The principle of direct fuel in- 

 jection into the combustion chamber has 

 been tried with varying results. The 

 original method was to maintain some 

 portion of the combustion space at a 

 very much higher temperature than the 

 rest, usually by having it unjacketed 

 This was not conducive to lubrication, 

 since the piston had a tendency to stick 

 when passing over the spot. The 

 fuel was supplied after the air was 

 taken in, but before the compression; 

 and, as there was often an insufficient 

 sup-ply of oxygen in contact with the 

 fuel during vaporization, the fuel some- 

 times "broke-up,"' leaving a heavy car- 

 bon deposit. Also when a vaporized 

 fuel at a higher temperature came in 

 contact with the cooler air during com- 

 pression, a further precipitation of car- 

 bon took place. This fact is particularly 

 true of kerosene. 



But in crude oil engines of the Diesel 

 type we have perfect carburetion of the 

 heavy oil. Pure air is compressed in 

 each cylinder by between seven and eight 

 hundred pounds' pressure, the resulting 

 temperature being above that required 

 for ignition of the fuel. Hence no igni- 

 tion apparatus is required. The fuel is 

 injected gradually, and burns during a 

 portion of the power stroke with enor- 

 mous expansive power, so avoiding the 

 extremely high initial pressure but main- 



