PART IV. METHODS OF TESTING CREOSOTES AND OFFICIAL 
SPECIFICATIONS FOR CREOSOTE. 
CHAPTER I. PRACTICAL METHODS OF TESTING CREOSOTES. 
A number of tests have been proposed for creosote which, in gen- 
eral, are of considerable service when materials of known source are 
to be examined. The 
< 6 m 
•oo h: ■ 
101 
tests fail, however, if an 
attempt is made to deter- 
mine whether the creo- 
sote under test meets the 
requirements for purity. 
The following tests have 
been proposed and used. 
SPECIFIC-GRAVITY TEST. 
x 
5 
CM 
102 
*03 
104 
105 
106 
107 
*■ J 
<32mm.> 
L —%L 
\ 
> 22 mm. <■ 
__ _xggyShot 
T 
Practically all specifi- 
cations for creosote re- 
quire that it shall have a 
certain range of specific 
gravity; sometimes it is 
stated that the specific 
gravity shall not be less 
than 1.03 or more than 
1.08, and sometimes that 
it shall not be less than 
1.03. The specific-gravi- 
ty determination is effec- 
tive only when straight 
distilled oils are used. Water-gas- tar oils have practically the same 
range. An oil of low specific gravity may be made to pass the 
specifications for coal-tar creosote by the addition of tar. This would 
also raise the distillation limits. The specific-gravity test, although 
it is an exceedingly useful one when used with creosotes of known 
origin, does not identify the oil or exclude tar. Any approved method 
of determining specific gravity will answer. An ordinary hydro- 
meter is generally used. The dimensions of the hydrometer and 
cylinder, and the details of the test adopted as standard by the 
American Society for Testing Materials, the American Railway Engi- 
87 
Fig. 40. — Hydrometer and cylinder used for specific-gravity test. 
