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Transactions Texas Academy of Science. 
Florida, and Tampa, Florida ; several of these, notably the one at Tampa, 
reporting very satisfactory progress. 
In reference to carbonaceous matter forming a detrimental outer coat- 
ing, I wish to say that it has been proved by practical tests that the 
closing of the poors of the wood will cause “dry-rot.” In Germany, tests 
were made by treating mining timbers with coal tar, lime, tar oil of the 
character above described, and the results were very much in favor of the 
latter. The timbers having received the tar coating, appeared sound 
externally, while the core was completely rotten. I may quote another 
instance where it was clearly demonstrated that outer coatings on timbers 
produced injurious results. Timbers that had been treated with a com- 
pound above referred to (tar oil distillate) were unaffected after years 
exposure, while other timbers of the same character that received a coat 
of oil paint after having been treated, decayed in a short time, thereby 
showing that the outer coating formed by the oil paint was the direct 
cause of the decay. This explains why coal tar is valueless as a preserver. 
A comparison of results leads us to the following conclusion : To pre- 
serve timber by means of superficial application, the substance used 
should be a coal tar distillate boiling above 270° C., free from low boiling 
(volatile) oils and carbolic acid ; that it should contain a high percentage 
of tar bases, notably acridine; and that it should be free from tary or 
insoluble carbonaceous matter which would close the pores. With such a 
substance the action is probably as follows : Let us assume that we have 
a piece of fairly seasoned wood which has been treated by painting with, 
or immersing it in this substance. Let it be exposed to the usual influ- 
ences it would meet with in the ground or in the air. Organisms that 
bring about decay are usually carried into the interior of the wood by 
moisture. Since the moisture can enter through the treated portion, it 
will absorb enougt antiseptics to render it germicidal, and hence the 
germs cannot operate extensively although they may have entered 
through some exposed place. 
