CONTENTS. 
Page. 
Introduction 5 
The nitrogen of Hawaiian soils 7 
Nitrate and ammonia 7 
Organic nitrogen 8 
Amids 9 
Basic nitrogen 10 
Nonbasic nitrogen 11 
Effects of aeration on soil nitrogen 11 
Humus nitrogen 12 
Nitrogen dissolved in the preliminary 1 per cent hydrochloric acid extrac- 
tion 13 
Separation of different forms of nitrogen in humus 14 
A.mid nitrogen 15 
Basic nitrogen 16 
Nonbasic nitrogen 17 
Determination of humus nitrogen 19 
Percentage of nitrogen in humus of Hawaiian soils 20 
Summary 21 
(4) 
