PAPERS OX CHEMISTRY AND PHYSICS 295 



PENETRATION TESTS IX "WOOD- 

 PRESERVATION 



George T. Parker and H. A. (Ieauque, Lombard College 



Wood-preservation has been carried on since the be- 

 ginnings of history but only since 1657 have scientific 

 methods been used. From 1657 to the present time the 

 growing scarcity of timber and the difficulty of replacing 

 decayed timbers have made it necessary to try in differ- 

 ent ways to lengthen its life with preservatives. The 

 first requisite for a preservative is that it be able to pre- 

 serve the timber from the common fungi. The next is 

 that it be in a form and of a price that renders it economi- 

 cal in application. It must be also of a nature so that 

 plant solutions can be handled easily and their strengths 

 easily controlled. 



Cresote oil is the standard organic preservative and 

 zinc chloride the standard inorganic preservative. Ma- 

 lenkowic seems to be the first man who used sodium 

 fluoride. In 1S87 he used it in connection with some or- 

 ganic compounds; tars, creosotes, nitrophenols, etc.. and 

 got very good results. In this country, tho. the chief 

 use of sodium fluoride has been in mine timbers. Some 

 of the mines in the anthracite region, Mr. L. W. Conrad 

 states*, used it for two reasons : Zinc chloride was very 

 hard to get at reasonable prices due to war conditions, 

 and it was thought that creosoted material increased the 

 fire hazard and rendered a fire harder to handle after it 

 was started. He also states that the minds were getting 

 about three years life from untreated mine timbers and 

 mine props while those that were treated with sodium 

 fluoride have given already five years life and are still in 

 good condition. The American Wood-Preservers* Asso- 

 ciation in January, 1922, prescribed as future work"* 

 for their committee on preservatives the development of 

 a volumetric and a gravimetric determination of sodium 

 fluoride, the direct determination of sodium fluoride in 

 treated wood, and if possible to develop a visual method 

 for determining sodium fluoride in treated wood. 



• American Wood-Preservers' Association Proceedings, 1921, page 183. 

 ••American Wood-Preservers' Association Proceedings, 1922, page 54. 



