BUSHONG.] Chemical Composition of Petroleum. OLT 
The higher fractions had become so highly colored as to render 
them opaque for examination in the polariscope. A few of the 
lower and clearer fractions upon preliminary examination 
gave indications of slight optical activity. In order to thor- 
oughly test the matter, the vacuum fractions of oil No. 3, from 
Urbana, which we had in largest amount, were redistilled and 
the fresh, slightly yellow colored samples were then examined 
in the polariscope by Mr. Frank Brock, with the following re- 
sults : SS) 1 Optical rotation 
Boiling-point. 25°-15° Ref. index. in a 200 mm. tube. 
195° at 88 mm. to 215° at 86 mm. 0.8454 1.4709 0.10° to the right. 
215° at 86 mm. to 228° at 87 mm. 0.8503 WAVaxS MILL Ss ss 
22S matic(emmato 22° at Simm sO85300 TATA OM5g 
239° at 87 mm. to 250° at 92 mm. 0.860 LAW  O285° ™ iM 
IDS? aii 25 mim, to 2B aeRO, O8G7 Mies ee oY 
237° at 30 mm. to 248° at 30 mm. 0.872 LARS OAs? % S 
DAS? ai 80 mim, to AIP ab adm, O87 WAG Ope 8 
250° at 28 mm. to 262° at 28 mm. 0.879 1.4895 0.61° es oh 
XO?” Ais ZB TMI, WO) AWA Bie PAY roatany, 0.881 1.4909 0.76° a 2 
NPA” BIG PAY VETO, (KO) Arev4> BB 7A teMaa\s 0.883 1.4920 0.98° e 
The same pronounced optical activity in the higher-boiling 
fractions has been recently observed in Roumanian petro- 
leum?®® and petroleum of the Ferghana district, Russia.**! By 
means of this optical activity chemists may be enabled to de- 
tect small quantities of certain constituents of the oils, and 
gain information regarding certain changes which these con- 
stituents are capable of undergoing. 
Notwithstanding the fact that petroleum has been mar- 
keted in vast quantities for many years, little use has been 
made of it except for fuel, illumination or lubrication. Coal- 
tar, which resembles petroleum in many respects, was formerly 
considered valueless, but now finds use as the raw material 
from which a very great variety of industrial products are be- 
ing manufactured. The development of these industries came 
only after the researches of scientists had revealed the presence 
of constituents previously unknown. Crude petroleum con- 
tains different classes of chemical substances that have never 
yet been studied sufficiently to enable us to make use of them. 
There may be great difficulties to overcome before processes 
for the utilization of these constituents can be developed, but 
the history of the progress of chemical industries in the past 
leads us to believe that when these difficulties are overcome far- 
reaching benefits of permanent value will be the result. 
260. Reinhard and Botez, Revue du Petrol, 1908, 10. 
261. Rakusin, Revue du Petrol, 1908, 146. — 
