A Dkl'Kxxiat. Kkcokd 149 



scale. Closely connected with tliis proljleiii is that of developing a 

 suitable artificial stone, and wliile many abrasive materials have been 

 suggested, and some tried, tlie problem is not as yet solved. But here 

 again the laboratory can be of great assistance. 



The importance of keeping under control the production of me- 

 chanical pulp is receiving increasing attention, and a number of years 

 ago was the subject of some study. Since that time, however, no op- 

 portunity has been presented for the laboratory to continue this Mork, 

 although mill organizations are carrying on investigations along this 

 line. 



The loss of fibre in Whitewater has ])een the subject of much 

 discussion in the past, both from the standpoint of stream pollution 

 and improving plant conditions. Because of the large volume of water 

 M'hicli must be handled in order to recover tlie relatively small amount 

 of fiber, certain difficulties present themselves at the start. But prog- 

 ress has certainly been made in the solution of this problem, and mucli 

 more can be done if the matter is made the subject of an intensive study. 



The effect of the various factors entering into the beating of pulp 

 is not entirely understood, although progress is being made along these 

 lines. In spite of the work that has been done with experimental beat- 

 ers it is not yet possible to apply the results obtained upon a small scale 

 to mill conditions. 



In connection witli the conservation of w\aste materials, the recov- 

 ering of various waste papers such as paraffine and asphalt commands 

 attention. Because of the difficulty of collecting these waste products, 

 but comparatively little progress has been made, although the laborn- 

 tory tests have successfully demonstrated that the impregnating mate- 

 rial can be recovered without undue cost and the extracted pulp made 

 into a satisfactory sheet. One mill is now being built for the extraction 

 of paraffine and the manufacture of the waste paper into pulp. 



The study of a suljstitute for sulphate of aliunina is a problem of 

 utmost importance at this time, and if transportation conditions re- 

 main as they are today, and seemingly no miracle is going to happen 

 to change these conditions under from three to five years, then we shall 

 need some substitute for this commodity wliich we can obtain easily, 

 possibly from some materials now employed in our pulp-making indus- 

 try. The conditions in the manufacture of sulphate of alumina today 



