Periodical Literature. 279 



Thorriias slag, such materials, can be used to make poor soils 

 more active, the organic contents stimulating bacterial growth. 



If the liquor of present processes cannot be utilized, other 

 liquors might be invented which may be useful as feed or fertil- 

 izer. This would, of course, revolutionize the whole paper pulp 

 industry and therefore is not to be expected at once. In the 

 leather industry, while the liquor does not have tanning values, 

 it can be used as a filler. 



The author then discusses the mechanical pulp industry when 

 only 10 to 20 per cent, of fiber is lost, and the brown pulp made 

 from steamed wood which produces a stronger fiber, and if the 

 steaming has not been carried too far yields a similar output, 

 saving much loss as against the chemical fiber. A better adapta- 

 tion of the cooking operation to the species involved is also a 

 problem. It appears that aspen is now so much used that an 

 Italian factory has begun to make plantations of it. Again the 

 question of the use of wood offal, especially with the bark on is 

 a problem unsolved, although beginnings have been made in the 

 United States, needing, however, an improvement in removing 

 the bark which is done by hot water in rotating drums. If this 

 use of ofifal is made practical a loss of 25 to 40 per cent, of the 

 wood consumption for pulp could be saved. 



The problem of the use of sawdust is then taken up. So far 

 neither dry distillation nor making feed or cellulose has been 

 practically successful, but may become so. 



Incidentally, it is mentioned that in Germany at present over a 

 million pounds of silk, worth one and a half million dollars is 

 made from cellulose. A ton of wood worth $10 yields 880 lbs. 

 of cellulose, worth $20, from which can be secured 750 lbs. of 

 silk worth $850 — an enormous value increase. ! 



This silk, as well as a film material, cellophan, is made by 

 treating cellulose with carbon bisulfide and caustic soda, which 

 turns it into a substance soluble in water, from which transparent 

 threads and skins can be formed, which in forming lose again the 

 solubility. 



Wood cellulose can also be worked into nitro-cellulose for ex- 

 plosives, and celluloid, but the product is less valuable than that 

 made from cotton — probably due to the admixtures in the wood 

 cellulose. If these can be overcome, an enormous gain for the 



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