70 
BULLETIN 1216, U. S. DEPARTMENT OF ACtRICULTURK. 
the cylinder are then thoroughly shaken and after standing the 
quantity of separated supernatant water read. 
A fj 
Calculations: Percent water - { . < 200 
A = volume of supernatant water. 
/>' = volume of 10 per cent calcium chloride solution originally 
used. 
C = weight of emulsion taken for water determination. 
TEST FOR WATER IN BITUMINOUS MATERIAL. 
(A. S. T. M. tentative method, serial designation 1> 114-21 r.) 
1. The apparatus shall consist of a copper still, (i inches h\ 3| 
inches inside diameter, with an adjustable ring burner to lit the 
stili. The still shall he provided with a connecting tube, ;i con- 
denser trough, ;i condenser tuhe. and a sep;iratory funnel. A 
thermometer, 0° to 250° C, shall be provided. The apparatus 
shall he set up as shown in Figure 7. 
'Thermometer 
Fig. 7. — Apparatus for dehydration test 
2. Fifty cubic centimeters of coal-tar naphtha or li.a'ht oil shall 
be measured, into a 250 cubic centimeter graduated cylinder, and 
200 cubic centimeters of the material to he tested shall be added, 
in the case of petroleum products, petroleum naphtha may he 
substituted for the coal-tar naphtha. The contents shall be 
transferred to the copper still and the cylinder shall be washed 
with LOO to 150 cubic centimeters more of naphtha, and the wash- 
ings added to the contents of the still. The Lid and clamp shall 
he attached, using a paper gasket. The condenser trough shall 
be filled with water. Heal shall be applied by means of the ring 
burner, and the distillation continued until the vapor temperature 
has reached 205° C. (401° F.). The distillate shall be collected 
in the separatory funnel, in which 15 to 20 cubic centimeters of 
benzol or naphtha have been previously placed in order to effect 
a (lean separation of the water and oil. The reading shall he 
