Wood Preserving by Painting with or 
Immersing in Tar Oils. 
E. P. SCHOCH. M. A., C. E., 
Instructor in Chemistry, the University of Texas. 
The value of good creosote as a wood preserver is beyond question, but 
the expense of the operation coupled with the fact that creosoting plants 
are not sufficiently numerous to be of easy access everywhere, reduces the 
advantages of the process so that in the erection of occasional small 
buildings by the farmer and others, they are almost nil. A wood pre- 
server that is easily and cheaply applied is highly desirable. The 
immense economic value of such an article needs no special emphasis. 
Everything considered, of all substances that have been extensively 
employed for the preservation of timbers, creosote has given the best 
and most uniform results. Hence in searching for an effective preserv- 
ing substance that is easily and cheaply applied, one should naturally 
begin by enquiring into the value of the different constituents of creosote, 
more particularly, the different coal tar distillates. 
It has long since been found that the efficiency of creosote varies 
greatly with different samples. Leaving out of consideration the many 
adulterated samples that we have to contend with in this country and 
confining ourselves to pure creosote oil, we find that the results obtained 
with samples from different tars have been clearly presented and well 
discussed by Mr. S. B. Boulton in a paper presented before the “Institu- 
tion of Civil Engineers” of England in 1885, entitled “The Preservation 
of Timber by the Use of Antiseptics.” From Mr. Boulton, and other 
authorities, I have gathered the following facts and conclusions con- 
cerning the value of different constituents of creosote : 
1st. — Carbolic Acid. Of all coal tar products, the tar acids first 
attract our attention. Carbolic acid is the best known representative of 
this class of bodies and is present in tar in larger quantities than any 
other acid. It is popularly thought that the preservative qualities of 
creosote are manily due to the presence of carbolic acid. However, as a 
germicide it is not as effective when compared with solutions of the same 
strength of other constituents of coal tar discussed further on. Accurate 
quantitative data on this point have so far not been obtained, but experi- 
ments have been outlined and partially begun at the Chemical Labora- 
