10 



BULLETIN 989, U. S. DEPARTMENT OF AGRICULTURE. 



Since it was desired to determine whether other oils from the de- 

 structive distillation of wood are active germicides, commercial sam- 

 ples of these also were collected and the samples analyzed (Table 3). 



Table 3.- 



-Composition of commercial samples of destructive-distillation 

 pine oils. 



Labora- 

 tory- 

 No. 



Description of 

 sample. 



Den- 

 sity 

 at 20°C 



Refrac- 

 tive 

 index 

 at20°C. 



Resin- 

 ous ma- 

 terial. 



Phe- 

 nols. 



Water. 



Oil distilled. 



Unpol- 

 ymer- 

 ized. 



Below 

 160° C 



160° C 

 to 180° 



c. 



180° C. 

 to 220° 



c. 



31710.... 

 31715 



Wood naphtha 



do 



0. S69 

 .869 

 .868 

 .919 

 .909 

 .946 



1.028 

 .975 

 1.020 

 1.003 

 1.049 



1. 015 



1. 4780 

 1. 4825 

 1.4700 

 1. 4965 

 1.4840 

 1. 5105 

 1. 5450 

 1. 5255 

 1.5460 

 1.5355 

 1. 5450 

 1. 5500 



Per ct. 



1 2. 59 



2.07 



.74 



11.90 



2.98 



19.70 



37.40 



20.10 



37.90 



26.80 



31.30 



22.60 



Per ct. 



0.54 

 2.43 

 3.85 

 5.30 

 4.40 

 6.20 

 5.80 

 4.80 

 6.40 

 9.70 

 6.00 



Per ct. 

 None. 

 None. 

 None. 

 None. 

 None. 

 None. 



0.6 

 None. 



1.0 

 .8 



1.0 

 .4 



Per ct. 



34.0 



' 83.0 



79.0 



12.0 



25.0 



4.0 



4.0 



19.4 



6.0 



6 4 



1.6 



2.0 



Per ct. 

 56.0 

 12.6 

 16.0 

 39.6 

 39.6 

 31.0 



8.0 

 14.6 



8.0 

 10.0 



1.0 



6.0 



Per ct. 

 6.0 



21.0 

 28.4 

 27.0 

 16.0 

 12.8 

 15.0 

 20.0 

 8.0 

 18.0 



Perct. 



0.8 



.g 



31716.... 



31717.... 



31720.... 



31723 



31719.... 



31718.... 



31721 



do 



Crude light oil 



do 



do 



Heavy crude oil. . . 

 Entire crude oil... 

 do 



.4 



Trace. 



.8. 



.4r 



None. 

 0.8 



31722 



do 





31725 







31726 



do 











1 Contained wood-tar phenols which were not separated. 



It will be noted that there is a rough relation between the boiling 

 points, densities, and indices of refraction of the crude oils, those 

 with the lower boiling points having the lower densities and lower 

 refractive indices. The unpolymerized residue is in all cases less 

 than 1 per cent. The resinous material and phenols are high in the 

 crude distillate, in some cases as much as 40 per cent. 



Pine oil obtained by the steam or steam-and-solvent process is a 

 very uniform product. That obtained from destructive distillation 

 is much less uniform. It consists of the same compounds as the 

 steam-distillecl product, together with the distillation products of 

 rosin and wood in various proportions, depending upon the particu- 

 lar manner in which the distillation was conducted. 



The crude distillation products also varjr greatly in their composi- 

 tion, depending on the practice at the plant where they were made. 



The unpolymerized residue in the case of all the products of pine 

 distillation is low, 2 per cent or less, except in one case in which the 

 oil had been in contact with petroleum distillate in the course of 

 manufacture and probably still contained a small amount of it. 

 Since petroleum oils, of course, give high polymerization residues, 

 this provides a method for detecting the adulteration of pine oil with 

 kerosene or other mineral oil fractions. 



PREPARATION OF PINE-OIL EMULSIONS. 



All of the samples collected, which were fairly representative of 

 the products of destructive distillation of the longleaf pine as carried 

 out commercially, were made into emulsifiable liquids by the method 



