104 BULLETIN 1036, U. S. DEPARTMENT OF AGRICULTURE. 
Table 36. — Specifications for coal-tar creosotes. 
[All creosotes listed must be a distillate of coal-gas or coke-oven tar, and, in addition, must fulfill these 
requirements.] 
Requirement. 
Moisture content 
Insoluble in benzol 
Specific gravity at 3S° C. referred to 
water at 15. 5 6 C 
Distillates up to 210° C 
Distillates up to 235° C 
Specific gravity of fractions at 3S° C. 
referred to water at 15.5° C: 
Fraction 235° to 315° C 
Fraction 315° to 355° C 
The float test must not exceed 50 sec- 
onds at 70° C. if the residue at 355° C. 
exceeds 5 p. ct 
Coke residue N. M. 2 p. ct . . 
N. L. 1.03 2....' 
X.M. 5p.ct I 
X. M. 25 p. ct. 
N. L. 1.03.. 
N. L. 1.10.. 
. ct. 
M. 2 p. ct. 
Specification Xo. 1= Grade 1, A. R. E. A.: creosote for ties and structural timber of A. W. P. A. 
Specification Xo. 2=Grade 2, A. R. E. A. 
Specification Xo. 3= Grade 3 ? A. R. E. A. 
Specification Xo. -4= Distillate oil for paving blocks, A. TV. P. A. and A. S. M. I. 
1 X. M.=Not more than. 
*N. L.= Xot less than. 
Table 37. — Specifications for coal-tar solutions. 
Requirements. 
Composition of solution . 
TVater content 
Insoluble in benzol 
Specific gravity at 38° C. referred to water 
at 15.5° C 
Distillates up to 210° C 
Distillates up to 235° C 
Specific gravity of fractions at 38° C. referred 
to water at 15.5° C: 
Fraction 235° to 315 C 
Fraction 315° to 355° C 
Float test must not exceed 50 seconds at 
70° C. if the distillation residue at 355° C. j 
exceeds 
Coke residue 
Specification No. 1. 
Specification No. 2. 
80 per cent distillate of coal- 
gas or coke-oven tar; 20 
per cent filtered or refined 
coal-gas or coke-oven tar. 
N. M. 3 per cent 1 
N. M. 2 per cent 
X T .L. 1.03 2 
X.M. 1.12 
X. M. 5 per cent.. 
X. M. 25 per cent. 
N.L.1.03 
N.L.1.10 
65 per cent distillate of coal- 
gas or coke-oven tar; 35 
per cent filtered or refined 
coal-gas or coke-oven tar. 
X. M. 3 percent. 
N. M. 2 per cent. 
N. L. 1.03. 
N. M. 1.14. 
N. M. 5 per cent. 
N. M. 25 per cent. 
N. L. 1.03. 
N. L. 1.10. 
26 per cent 
N. M 
6 per cent . 
!5 per 
ST. M. 
10 per cent. 
Specification Xo. l=Tar solution for ties and structural timber of A. R. E. A. and A. TV. P. A. 
Specification Xo. 2= Tar solution for paving blocks of A. TV. P. A. and A. S. M. I. 
1 X. M.= Xot more than. 
2X. L.= Xot less than. 
WATER-GAS TAR. 
Up to the present time no specifications have been adopted for 
either water-gas tar or water-gas-tar creosotes to be used alone as a 
wood preservative. The American Railway Engineering Association 
adopted in 1920 a specification for water-gas tar distillate and a spec- 
ification for water-gas tar solution to be used in conjunction with 
zinc chloride by any of the preserving processes employing both zinc 
chloride and oil. The requirements of these specifications are given 
in Table 38. 
