112 
Indian Forest Records. 
[Vol. VI 
The oil actually used had a specific gravity 1*04 at 38°C., 13 per 
'Cent, by volume of Tar acids extracted at 38°C., no distillate at 200°C., 
I' 2 per cent, at 210°C., 11-2 per cent, at 235°C., and a soft residue 
comprising 22 per cent, of the total volume remaining at 355°C. This 
specification is the one adopted for grade I oil by the American Railway 
Engineers Association. 
Grade II oil, as specified by the Association, is similar to the above, 
with the following modifications that 8 per cent, is allowed to come over 
below 210°C., and not more than 35 per cent, below 235°C. 
The United States Department of Agriculture, Forest Service, 
Circular 112, by Messrs. A. L. Dean and E. Bateman, entitled “ The 
Analysis and grading of creosotes,” gives the analysis of an A grade oil, 
which is well adapted for Open Tanh treatment, where excessive 
loss from volatilization is possible during the process. It runs as 
follows*:— 
Percentage of distillate. 
Nil to 2 per 
10 
20 
30 
40 
50 
60 
70 
cent, from 
99 99 
99 99 
Temperature ranges. 
. 200°C. to 230°C. 
. 218°C. to 240 tf C. 
. 225°C. to 260°C 
. 230°C. to 289°C. 
. 238°C. to 3ll°C. 
. 257°C. to 326°C. 
. 285°C. to 340°C. 
. 306°C. to 354°C. 
The remainder as residue. 
The above are the maximum and minimum percentages permissible 
in A grade oil. Taking an average of these extremes, a high grade creo¬ 
sote oil would be obtained, with boiling fractions, as given below :— 
Distilling at 210°C. 
„ „ 220°C. 
„ 230°C. 
„ „ 240°C. 
„ „ 250°C. 
„ 260°C. 
„ „ 270°C. 
„ „ 280°C. 
„ „ 290°C. 
„ „ 300°C. 
„ „ 310°C. 
„ „ 320°C. 
„ „ 360°C. 
Per cent. 
. Nil 
. 5 
. 10 
. 15 
. 23 
. 30 
. 37 
. 43 
. 47 
. 50 
. 55 
. 60 
80 
* Note.— These figures are given in diagrammatio form in the above quoted publication 
[ 24 ’. ] 
