February, ’18] MOORE AND GRAHAM: TOXICITY OF KEROSENE 71 
erably in composition due to its manner of preparation. Some are 
placed on the market directly as they are obtained in distillation,, 
while others are further purified. Some consist of heavy oils which 
have been diluted with naphtha to give them the proper flash point, 
while others are heavy oils which by a special process of distillation* 
known as cracking are broken up into oils having a lower boiling point, 
thus enabling them to pass the flash test. In addition to these and 
other types of kerosenes which may be obtained from the same source 
there might be mentioned an almost endless number of variations 
depending upon the source. The petroleum obtained from the fields 
of Pennsylvania, Illinois, Indiana, Texas, California, Canada, Russia, 
and other places, to which may be added the Scotch shale oil known as 
paraffin oil in England, all vary to some extent in their chemical com¬ 
position. Not only do they vary in minor constiuents but even as 
to the series of chemicals which they contain such as the Pennsylvania 
oil with its paraffin base and the California oils with their asphaltic 
base. With these variations in mind five different oils were obtained 
for this study. Two of these were obtained from the same field but 
were decidedly different oils while the other three represented different 
oil fields. Only American oils were used as it is doubtful if foreign 
oils are usually encountered on the American market. The oils may 
be conveniently referred to as A, B, C, D, and E; A and B represent¬ 
ing oils from the same field but differing in that A was more refined 
and a more expensive oil than B. C, D and E represented oils from 
other fields. These oils were all fractionally distilled into four parts 
with the idea of obtaining compounds of a more even chemical com¬ 
position and with a smaller range of boiling points. Table I shows 
the different boiling points of the fractions and the per cent of each 
fraction to the whole. 
Table I 
Oil 
First Fraction 
Second Fraction 
Third Fraction 
Residue 
Boiling 
Point 
% 
Boiling 
Point 
% 
Boiling 
Point 
% 
Boiling 
Point 
% 
A 
140°-187° 
27.2 
187°-234° 
42.6 
234°-280° 
28.2 
280° + 
1.9 
B 
160°-200° 
19.5 
200°-240° 
57.7 
240°-280° 
21.0 
280° + 
1.7 
C 
135°-183° 
11.1 
183°-231° 
66.6 
231°-280° 
22.2 
.... 
D 
150°-195° 
20.0 
195°-240° 
60.0 
240°-285° 
20.0 
.... - 
• • ♦. 
E 
150°-185° 
37.4 
185°-235° 
46.0 
235°-260° 
12.2 
260° + 
4.4 
Results of Experiments 
Toxicity to Plants 
The toxicity to plants was tested by spraying tomato plants, in the 
