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UNITED STATES DEPARTMENT OF AGRICULTURE | 
BULLETIN No. 620 . pas eae | 
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Contribution from the Forest Service 
HENRY S. GRAVES, Forester 
Washington, D.C. PROFESSIONAL PAPER March 14,1918 | § 
EFFECT OF VARYING CERTAIN COOKING |f 
CONDITIONS IN THE PRODUCTION OF j|§ 
_ SULPHITE PULP FROM SPRUCE 
. ' : . By. 
S. E. LUNAK, Chemist in Forest Products 
CONTENTS | Pe 
Purpose of the Experiments Effect of Varying the Ratio of Free te 
The Sulphite Process Combined SO, or the Amount of Lime 
- Kinds of Wood Used 7 in the Cooking Liquor . 
Effect of Varying Total Sulphur Dioxide . 
Present Methods of Operation . . . . 
Plan of Tests Effect of Varying the Temperature of | 
Cooking . « « «© «© © «2 
Apparatus . sie Summary of Results 
Method of Conducting Experiments . . Methods of Analysis and Other Tests 
Analysis of Cooking Liquor | 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1918 
