CONTENTS. 



Page. 



Need of a substitute for spruce pulpwood 5 



Results of experiments 6 



Why jack pine and hemlock have not been used for pulp 7 



Equipment used in the experiments 8 



Electrical equipment 8 



Pulp machinery and auxiliary equipment 8 



Methods employed 10 



Qualitative and quantitative tests. ..'. 10 



Commercial tests 10 



Treatment of the wood before grinding 10 



Grinding 31 



Losses in grinding. 12 



Fiber study 12 



Calculation of results 12 



Comparison of yields 13 



Factors which influence quality and production 15 



Speed and pressure 15 



Surface of stone 16 



Temperature 18 



Undetermined factors , 18 



Microscopic comparison of experimental pulps and commercial standards 18 



Standard pulps 



Jack pine pulp 20 



Hemlock pulp 



Mixed pulps 



Samples of paper produced 



Summary of data 23 



3 



