REVIEWS 77 



little in places, omitting specifications and grading rules, which are 

 constantly subject to change, and leaving strictly foreign products out 

 of detailed consideration. In this way the general subject of forest 

 products would have been divided into two logical parts, one closely 

 associated with lumber, the other concerned primarily with products 

 other than lumber. S. J. R. 



Utilisation of Waste Sulphite Liquor. By Dr. Bjarne Johnson and 

 R. W. Hovey. Bui. No. GG, Forestry Branch, Dept. Interior. Canada. 

 Ottawa, 1919. Pp. 195. 



At least one-half of the dry weight of the wood used in the manu- 

 facture of paper pulp by the sulphite process is contained in the waste 

 liquor and for the most part is discharged from the mills as a useless 

 waste. It accoiKlingly becomes a matter of the first importance to the 

 industry to find practical methods of utilizing these potentially valuable 

 organic products. 



The importance of the subject has been recognized and this publica- 

 tion contains the names of 850 persons who have reported officially on 

 it. "But in spite of the large amount of work that has already been 

 carried out in connection with this question and notwithstanding the 

 fact that a few processes for the utilization of waste sulphite liquor 

 have gained industrial importance in some countries, the problem is 

 far from being solved. It cannot be considered to be solved before 

 a process or a combination of processes is established which will utilize 

 all the substances in the liquor so that products will be derived there- 

 from in an economical way and in a quantity and quality which will 

 enable them to compete with present products on the market." 



The object of the compilers of this publication has been to collect 

 all available information and condense it into a form which will be of 

 the greatest usefulness to the industry as well as to those who wish 

 to engage in research in this promising field. The data on this subject 

 are so widely distributed in the literature, and especially in foreign 

 publications which are not readily if at all available here, that the com- 

 pilers have done a great service in bringing it together in the present 

 volume. The plan has been to cover all of the literature, making the 

 most imjiortant abstracts as complete as possible and arranging the 

 information into chapters according to the nature of the recovered 

 products. In the general introduction and the introduction to the more 

 important chapters the situation, the problems and the difficulties arc 

 summed up in a very concise and helpful manner. 



