208 
OTL DISTRICTS OF SOUTHERN CALIFORNIA. 
filling and to intercept any liquid spurted out during the distillation. I do not give 
the measurements of the flask, because in California we have to take what we can get 
in the line of glassware. But if the flask holds 300 to 325 c. c. up to the bottom of the 
neck, the diameter of the neck is about one-fifth the diameter of the bulb, the exit tube 
joined to the neck halfway between the top of the bulb and the top of the neck, and the 
neck about one and one-half times as long as the diameter of the bulb, the flask will 
fulfill the requirements. To prevent condensation in the upward bend it is sur- - 
rounded by fluffed asbestos fiber about half an inch thick. The exit tube should be 
30 inches long from the top of the bend to the tip of the tube. The thermometer is 
placed so that the top of the bulb is level with the bottom of the exit tube. During 
the distillation up to the 250°-300° fraction the exit tube passes through a water con¬ 
denser. After this fraction passes over the condenser is removed and the exit tube 
used as an air condenser. 
The specific gravity of the sample is first determined; then the flask is placed on one 
pan and counterbalanced with shot. The balance must be accurate to 50 mg. with a 
300-gram load. Enough oil is poured in to make a volume of 200 c. c. (calculated from 
the specific gravity) at the temperature of the room in which the distillation is to take 
place. The condenser is attached, the 50-c. c. graduated cylinder put under the tip of 
the exit tube, and the oil is cautiously heated until all the water is driven over. In 
making the fractional distillation I do not recommend putting in any measured amount 
of gasoline or other light-boiling liquid to drive off the water. I have never seen a 
sample that could not be fractionated in its original condition, if care and patience are 
used. The oil is then fractionated between the following temperatures: Up to 100°, 
100°-150°, 150°-200°, 200°-250°, 250°-300°, 300°-asphalt, asphalt. The flame is so 
regulated as to cause the oil to distill over no faster than two drops per second. Just 
before the thermometer reaches the point where the distillation is to be stopped the 
flame is moderated to allow the thermometer to rise gradually to the stopping point. 
The flame is now removed to allow the temperature to fall, 20° for the 100° fraction, 
100° for the 300° fraction, and a proportionate fall for the fractions in between, and 
then heated up again. This is repeated until no more than three drops can be squeezed 
over. The receiver is then changed and the next higher distillate run over. An 
exception must be made with the 250°-300° fraction, if much cracking takes place. 
With some oils very varying results may be obtained for the 250°-300° fraction, because 
every time the temperature goes up to 300° cracking takes place and more distillate 
passes over. In such cases I have arbitrarily stopped at 50 c. c. and made a note to that 
effect in the tables (the fraction is marked [&]), or else I have kept the temperature at 
290° until the cracking had almost stopped. This last procedure is too long to be 
practical, and I recommend the former. The asphalt was run down to grade D. It 
was tested by running a looped wire down the neck of the distilling flask, drawing out 
a drop and testing it by chewing or by the finger nail. Of course, with such small 
quantities it does not make much difference in the results whether the asphalt is run 
down to grade C, D, or E. The asphalt is measured in this way: Fill the flask with 
water to a mark on the neck; pour out the water and save for future use. Dissolve the 
asphalt in waste lubricating oil (heat the flask over the flame) and remove the traces 
with gasoline and then with hot sulphuric acid and potassium bichromate. Dry, and 
pour back the water. Now run in water from a burette to the mark. The number of 
cubic centimeters run in represents the asphalt. 
