Periodical Literature. 747 



Tarry Acids (Phenol, Kresol etc.) 

 Calcium-Cresol 



Dinitrophenole and Dinitrobenzole 

 Hydrofluoric acid (H Fl) 

 Fluorzinc acid (Zn FI2 2H Fe) 

 Neutral fluorzinc (Fn FI2) 

 Neutral fluor sodium (Na Fl) 

 Acid fluor sodium (Na Fl H Fl) 



Every rot fungus species reacts characteristically to the different 

 poisons ; one species may be readily killed by a given poison, while 

 another may be not at all or little affected in its growth by the 

 same. 



So far too little positively is known as to the durability attain- 

 able by use of different poisons. All careful investigations have 

 shown that the much praised copper sulphate is a weak antiseptic ; 

 and so the Boucherie process, the author states, is well nigh for- 

 gotten, although a few establishments still use it and the German 

 Post Administration still employs it for about 50 percent of its 

 needs for telegraph poles, and in France and Netherlands it re- 

 mains still in vogue with assistance, however, of creosote oil paint- 

 ing and tin covers at the ends, or by immersing ends in hot solu- 

 tions of thin creosote oil — an expensive process. 



Zinc chloride (see table) has proved itself not much better as 

 an antiseptic, while the effectiveness of chloride of mercury is 

 bringing the old Kyanizing process (patented in 1832) again to 

 honor, this poison having been found 15 to 20 times as effective 

 as copper sulphate. The experience of the German Post Ad- 

 ministration has verified this theoretical result practically: tele- 

 graph posts treated with the Boucherie process lasted in the 

 average 11.7 years, Kyanized ones 13.7 years or 17% longer, 

 while the cost of the latter were only 5% higher. In the last few 

 years this process has therefore been more widely used, 25% of 

 the Imperial Post administration's requirements, say 100,000 

 poles, and as many for other electric companies being treated by 

 it, as well as in other parts of Germany and in Australia. 



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