(Contribution from the Marine Laboratory, University of Miami) 



accelerat::;d test li .thod: of ;iiti-wrim': borer treati/Ients 



by F. G. V/alton Smith 



For many years the majority of investigations concerned viith the prevention 

 of m.^ine borer attack Tirere of a decidedly empirical nature. Although 

 records of marine borer attack arc found in the v/ritings of antiquity, the 

 descriptions of robective methods have consistently sounded like handbooks 

 on -virit Che s' caldrons. Yfi.th ferr exceptions, only in the present century has 

 a more scientific approach been adopted. Even now the old capricious habit 

 of aimlessly mixing all available unpleasant materials has not been com- 

 pletely abandoned. The results of centuries of empirical tests have shown 

 clearly, however, that no other preservative has ever been found with the 

 effectiveness and lon^ life of pressure-creosote treatment. It was only 

 natural, then, that steps should be taken during the past 30 years to 

 analyze the effects of creosote upon marine borers themselves, to compare 

 a wide range of other toxic compounds with creosote and to attempt to 

 isolate the effective agent in creosote. Experiments of this nature are 

 well sumnarized in EiARIME ST^IUCTIIRBS, THEIR DETERIORATION AND PRESERVATION 

 published by the National Research Council in 1921;. 



Unfortunately, experiments of this nature are not sufficient. It is not^ 

 enough that a preservative should be harmful to an organism immersed in it. 

 There are any number of substances normally found even in a household 

 closet capable of killing marine borers under these conditions. Shipworms 

 will undoubtedly die in a solution of household ammonia, rat ooison, sodium 

 pentachlorphenate, or even whiskey and soda. But none of these materials - 

 poisonous though they are - will, vihen introduced into wood, continue to 

 protect it against the marine borer for considerable periods of time, in the 

 manner that creosote does* 



Nevertheless, some kind of a test is necessary and it should preferably be 

 a test of the wood treatment rather than a simple pharmacological test of 

 the preservative independent of the treatment itself. The most direct 

 method, of course, is to impregnate a series of test panels with the com- 

 pounds under investigation, and to expose them in seawater to marine borer 

 attack. Unfortunately for this method the criterion of success is a treat- 

 ment which will protect the wood for a period of a good many years. The 

 resultant delay in obtaining controlled experimental data is therefore very 

 considerable. This, in itself, is a serious objection and undoubtedly ex- 

 plains the slow progress vrhich has been made in setting up creosote standards, 

 or in finding acceptable substitutes for creosote. 



In the course of the program of marine borer research at Miami, it was 

 early realized that a more rapid test of preservative treatments ^vas necessary 

 and the present report concerns the results of a search for such a test. An 

 interesting parallel to this problem and one which has provided a basis 

 for developing the desirable accelerated test is that which concerns anti- 

 fouling paints. In this case the problem was to develop a rapid test of 



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