Preservation of Mine Timbers 311 



timbers of the creosote treatment is closely connected with the 

 restoration of the oil by a suitable operation. 



Similar to creosote is the sodium creosote (Kreosotnatron) 

 which has been used for many years in Gennan and English 

 lignite mines. This results from the treatment with sodium 

 hydroxide of the lignite tar for the purpose of working it up into 

 parafifine and lubricating oil. A residue is formed, composed of 

 sodium hydroxide, water, phenol and neutral oils. It has a slight 

 advantage over creosote in that it is less inflammable. It is unde- 

 sirable for many purposes, and, especially in places where tim- 

 bering is to remain in use for several years, it is found that the 

 sodium creosote in the course of time makes the wood fibres 

 brittle through the effects of free sodium hydroxide. 



If we consider merely the increased life and the resulting 

 economy, creosote products could undoubtedly be looked upon as 

 extraordinarily valuable wood preservatives. Nevertheless, their 

 application in mine construction to-day must be looked upon as 

 on the decline. Most mines have, indeed, abandoned creosote 

 again, and have hurried to salt treatment. Bergassessor Stenz, 

 with the authority of his extensive experience as director of one 

 of the largest mines, gives the following as the most important 

 factors militating against the application of creosote in mining 

 construction. "Creosote has an unpleasant odor. Many people 

 refuse to work where there is wood treated with creosote. 

 Furthermore, creosote causes an appreciable increase in the fire 

 hazard. Where people sweat at their work — and this is always 

 the case in mining — the oil produces very unpleasant skin dis- 

 eases." The present writer can testify from his own experience, 

 also, that in horizontal workings where the outside weather con- 

 ditions can never have any very great effects, the creosote evapor- 

 ated under the influence of the high temperature of the mine 

 attacks the eyes especially in a very perceptible manner. In the 

 Mariemont Mine, which used the creosote treatment for many 

 years, it has been abolished for this reason alone. A further dis- 

 advantage is the greatly increased weight of the wood. In the 

 case of pine, for instance, a penetration of 6.3 pounds of oil per 

 cubic foot of wood means an increase of 20 per cent in weight. 

 Furthermore, woods treated with creosote are much harder to 

 work and soil the clothes of the workmen in a very disagreeable 

 manner. 



