FOREST PRODUCTS LABORATORY. 21 



soon as funds and equipment become available. The suitability for 

 paper making of hull fiber and second-cut cotton linters, formerly of 

 little value, has been demonstrated and a method of preparation worked 

 out that has proved commercially successful. 



PULP DECAY. 



A recently begun investigation of the deterioration of pulp wood and 

 wood pulp through fungous infection, now estimated at $5,000,000 a year, 

 is leading to the proper remedies for this great economic loss. 





DERIVED PRODUCTS. 



HARDWOOD DISTILLATION. 



The distillation of hardwoods for the production of wood alcohol, 

 acetate of lime, and charcoal offers one of the best methods for the utiliza- 

 tion of hardwood wastes, such as tops, limbs, and slabs. The first work 

 of the Laboratory along this line was a study of the comparative value of 

 different species as distillation woods at that time only beech, birch,* 

 and maple were used commercially. All the important hardwoods have 

 been tested, and several new species, such as oak and hickory, are now in 

 use. 



Methods have been developed whereby the yield of alcohol and acetate 

 can be considerably increased by a system of temperature control with- 

 out extending the time of distillation and with a decrease in the amount 

 of fuel required. These methods have been adopted by most of the 

 commercial plants. Encouraging results have been obtained in work 

 now under way on other methods for increasing the yields, such as the 

 treatment of the wood with chemicals previous to distillation. 



The production of flotation oils from hardwood tar is a promising 

 method of utilization which has been the subject of much investigation 

 of the Laboratory. Several satisfactory flotation oils have been pro- 

 duced, and the commercial utilization of hardwood tar is increasing. 



