As is evident from the gas chromatograms shown in Figures la, 2a, 

 3a and 4a, Fuel Oil D had the highest proportion of low boiling components, 

 whereas Fuel Oil C had the lowest proportion of low boiling components. 

 All of the distillate fuels had negligible components with more than 

 about 22 carbon atoms. Fuel Oil C had a very narrow boiling range; it 

 not only had the lowest proportion of low boiling components, but 

 it also had the lowest proportion of high boiling components, which 

 included very little material with over 20 carbon atoms. 



Evaporation of Thin Oil Films 



Samples of the fuel oils were put into flat weighing dishes 

 and these were placed in a current of air and were weighed periodically. 

 The fifty-milligram samples of the oils, with specific gravities 

 of about 0.85, have volumes of about 59 microliters; and in dishes 

 25 mm square, these should form films slightly under 0.1 mm thick. 

 The dishes were placed at the opening of a partly closed fume hood 

 and they were rotated after each weighing to provide nearly equal 

 exposure for each oil. The temperature of the room was approximately 

 25°C. The percentages of the oils remaining are shown in Table 2, 

 and are plotted in Figure 5. 



Table 2. Evaporation of Thin Films 





Percentage 



of Oil Remaining After 





Fuel Oil 













1/4 day 



1 day 



2 days 



3 days 



6 days 



8 days 



A 



70 



40 



23 



15 



4.3 



3.9 



B 



63 



43 



26 



16 



3.0 



2.4 



C 



82 



58 



42 



33 



5.0 



1.9 



D 



64 



44 



29 



17 



5.5 



5.4 



E 



83 



73 



69 



68 



64 



64 



