278 Forestry Quarterly. 



with cellulose the wood substance, are colloids, non-crystallizable, 

 hence difficult to study. 



The author then gives a rapid survey of conditions and prob- 

 lems of the chemical wood technology. 



The problems of wood impregnation are to find out the distribu- 

 tion of impregnating fluids and their possible secondary decom- 

 position or solution and the depth of their penetration. 



The problems of dry distillation, which besides charcoal, fur- 

 nishes wood vinegar, wood alcohol and aceton as basis for a long 

 list of chemical products — such as colors and varnishes, are in 

 part solved, since the importance of accurate temperature regula- 

 tion has been recognized and attended to. While these products 

 are mainly secured from hardwoods, there is a possibility to se- 

 cure from conifers other valuable products, such as spirits of 

 turpentine and rosin, which find application in the varnish indus- 

 try, artificial camphor, and in the paper industry. The problem is 

 to extract these materials without injuring the wood fiber, so that 

 it can be used for paper pulp which needs non-resinous woods. 



In the latter industry which in Germany produces 700,000 tons 

 of cellulose valued at $30,000,000 a number of problems remain 

 unsolved, especially how to utilize the spent liquors. 



In the soda process the recovery of the alkali, which has a rel- 

 atively high value, is connected with the production of evil smell- 

 ing gases, which makes it objectionable in civilized communities. 

 The sulphite process is not applicable to resinous woods, and in al- 

 lowing the liquor to run away into rivers not only are these pol- 

 luted but many tons of organic substance as there has been pro- 

 duced cellulose are lost. 



To find use for this enormous amount of waste material is the 

 great problem. In Sweden for a few years alcohol is recovered 

 from this liquor 60 liter to the ton of cellulose, but this represents 

 only 8 per cent, of the dry contents of the liquor, or i per cent, 

 of the liquor itself. 



Another use is as binding material for ore briquettes and coal 

 briquettes, but the high cost of evaporating the liquor, the increase 

 of ashes in coal briquettes, and their inconstancy under the influ- 

 ence of weather prevent this use. Attempts to use it either for 

 feed or fertihzer deserve full consideration, for here large 

 amounts could be utilized. Mixed with nitrates of lime and 



