86 BULLETIN 1036, IT. S. DEPARTMENT OE AGRICULTURE. 
wood had been preserved from the fungus attack in some way or 
other, although it apparently contained no creosote. Sections of 
this untreated but preserved wood were taken, and any portions 
that showed signs of containing creosote were carefully removed. 
The remainder of the wood was then reduced to sawdust. A portion 
of this was extracted with water in a Soxhlet extractor in such a 
way as to retain the tar acids, if any were present, in the water. 
Another portion treated in the same manner was extracted, but in 
such a way as to retain the tar bases, if any were present. The solu- 
tions thus obtained, upon being neutralized, gave odors similar to 
those obtained from tar acids in the one case and from tar bases in 
the other. A second extraction with benzol of the wood previously 
extracted with water gave a residue of perfectly clear rosin, in which 
there was not the least sign of creosote odor. From this it seems 
apparent that this inner ring of untreated material had been pre- 
served by the water-soluble material that came from the creosote 
and had been diffused through the wood. On the other hand, from 
coal-tar creosote a high-boiling oil has been isolated, which is prob- 
ably a mixture of anthracene, phenanthrene, acenaphthene, and 
their hydrides. This oil is practically nontoxic, for fungus grows on 
agar agar containing 20 per cent of the oil. 
The theory assumes that any toxic material which is more soluble 
in oil than it is in water will be less toxic at the start if oil is present 
than it would be in its absence. That is, if it takes 0.05 per cent of 
some material in water alone to kill an organism, it might take as 
much as 2 per cent if the material were dissolved in oil. On the 
other hand, any reserve material would not be removed so rapidly 
by leaching in the presence of oil as in its absence. Under similar 
conditions the speed at which creosote will be rendered nontoxic by 
leaching will depend on two things — the relative solubility of the toxic 
oils in the nontoxic oils and in water and the proportion of non- 
toxic oils present. If too little of the nontoxic oils is present, then 
the toxic material will be washed away very rapidly, because there 
would be little or no retaining influence exerted by the nontoxic 
oils. On the other hand, if there is too large an amount of non- 
toxic oil, the toxic oils will be prevented from going into solution in 
the water in a sufficient concentration to kill the attacking organism, 
and consequently these oils would not act as preservative. 
