312 Forestry Quarterly 



The use of salt solutions for the preservation of wood for 

 mining purposes, also, so far presents very few data. This is 

 somewhat strange, since we know that the preservative influence 

 of solutions of metallic salts has been known from time imme- 

 morial. This neglect can be explained by the fact that in olden 

 times the value of wood was very small in comparison with that 

 of the metal. In the renowned Spanish copper mines at Rio 

 Tinto, which were mentioned even by the Greek traveler 

 Diodorus Siculus, there is timbering which has lasted from the 

 time of Caesar. Also, there has been timbering standing in use 

 for centuries in the salt mines of Hungary and Galicia. In the 

 year 183T, Dr. Granville proposed to dip wood for mines in the 

 mother liquor from salt pits. In the years 1835-40 the director 

 of the mines at Dieuze made more extensive tests with wood 

 treated in a similar manner. In the year 1893, Aitken estab- 

 lished two vats at the Nidrie Mine in Scotland in which he treated 

 mine timbers in a concentrated solution of common salt and mag- 

 nesium chloride. This mixture of salts occurs in nature under 

 the name of Carnallite. 



Mining practice is broken up into countless independent sys- 

 tems, isolated from one another, which experiment now with 

 this, now with that type of preservative treatment, according to 

 personal inclination and familiarity with inventions and diverse 

 conditions of production in different mines, and naturally, at 

 first those methods were involuntarily given preference which 

 were the most loudly recommended. As a general rule, however, 

 it is not the older methods, known for many years, which praise 

 themselves. For this there are in several cases definite reasons. 

 The disadvantages of creosote treatment have already been indi- 

 cated in a preceding paragraph. There are objections, also, to 

 the use of the Boucherie treatment for mine timbers. This 

 method of treatment is adapted, as is known, only to freshly 

 felled timber. That presupposes, however, that the purpose for 

 which the wood is intended and the purchaser are known at the 

 time of cutting, because practically no timber dealer will give 

 timbers, especially mine timbers, a preservative treatment in ad- 

 vance when he does not know definitely that the same will find a 

 purchaser. Treatment with zinc chloride has fteen tried in a few 

 instances, but because of insufficient protective value has been 

 again abandoned. Kyanised wood, that is, wood treated with 



