80 DEPARTMENT BULLETIN 1216, U. S. DEPT. OF AGRICULTURE 
PREPARATION OF SAMPLE 
7. The sample, as received, shall be thoroughly stirred and agitated, warming, 
if necessary, to insure a complete mixture before the portion for analysis is 
removed. 
8. The material may be tested for distillation without dehydration, if water is 
present not to exceed 2 per cent. If water is present in excess of 2 per cent, 
the bituminous material shall be dehydrated before distillation in accordance 
with the method for dehydration as given in sections 2 to 4 of the standard 
methods of sampling and analysis of creosote oil (serial designation D 38-27) 
of the American Society for Testing Materials (see p. 93). 
PROCEDURE 
9. (a) The flask shall be supported on a tripod or rings over two sheets of 
20-mcsh gauze, 150 millimeters square, as shown in Figure 32. It shall be 
connected to the condenser tube by a tight cork joint. The thermometer shall 
be inserted through a cork in the neck with the top of the bulb level with the 
lowest point of juncture of the tubulature and neck of the flask. 
(&) The axis of the flask through the neck shall be vertical. 
(Thermometer 
t- Cork Stopper 
Fig. 32. — Distillation apparatus assembly 
(c) The distance from the bulb of the thermometer to the outlet end of the 
condenser tube shall be not more than 600 nor less than 500 millimeters. The 
burner should be protected from draughts by a suitable shield or chimney. 
(Fig. 32.) 
10. (a) One hundred grams (100 grams±0.1 gram) of the sample shall be 
weighed into the flask, the apparatus assembled and heat applied so that the 
first drop comes over in from 5 to 15 minutes. The distillation shall be con- 
ducted at the rate of between 50 and 70 drops per minute and the distillate 
collected in weighed receivers. The condenser tube shall be warmed whenever 
necessary to prevent accumulation of solid distillates. The fraction shall be 
collected at the points designated by the specifications. The receivers shall 
be changed when the thermometer indicates the maximum temperature for 
each fraction. When the maximum specified temperature of the test is indi- 
cated by the thermometer, the flame shall be removed and any oil which has 
condensed in the condenser tube shall be drained into the last fraction. 
(b) The residue shall remain in the flask with the cork and thermometer in 
position until no vapors are visible and it shall then be weighed. If tests of the 
residue are required, the flask shall then be inclined so that the residue will 
flow around the sides, thus collecting any condensed vapors that may be on the 
