COAL-TAR AND WATER-GAS TAR CREOSOTES. 
39 
obtained in the fractions boiling between 280° and 290° C, but some- 
times not under 300° C. Above and below these points the sulphona- 
tion residues decrease. The results shown in these figures seem to 
indicate that the kind of coal from which the tar is manufactured 
1.090 
'// 
'/, 
1.060 
/ 
1050 
f 
4 
°s K0, ° 
V 
S 
I 
IL 
1 
0. 
I 
/ 
/ 
1 
/ 
/ 
1 
/ 
// 
h 
1.040 
/// 
' / 
V. 
/ 
A 
'1/ 
U 
', 
/ 
>- 
/ 
MC0 
/ 
. t 
1 _, 
t -J- 
- 1 1ft 
-7 -J 
1 + 
J' 
r 
/ 
/K 
*A 
/ 
W- 
5^^ 
Fig. 19 
240 260 280 300 320 240 . 260 280 300 320 
TEMPERATURE - °C 
C D 
■Specific gravities of fractions of authentic coal-tar creosotes. 
A. Horizontal-retort tar creosotes. 
B. Inclined-retort tar creosotes. 
Dotted line — Vertical-retort tar creosote. 
C Semet-Solvay tar creosotes. 
D. Otto tar creosotes. 
Dotted line — Koppers tar creosote. 
has at best only a slight influence on the quality of the creosote pro- 
duced from coal tar, since in the range shown for horizontal retorts 
(figs. 18a, 19a, and 20a) Westmoreland, Youghiogheny, Alabama, and 
Tennessee coals were used, as well as mixtures of unknown or local 
coals with the above. The wide variation in the properties of coal- 
