|
Beginning of Boussingault's researches (1834)
|
21
|
|
Publication of Liebig's first report to the British Association
|
24
|
|
|
Refutation of "humus" theory
|
26
|
|
|
Liebig's mineral theory
|
26
|
|
|
Liebig's theory of source of plants' nitrogen
|
27
|
|
Publication of Liebig's second report to British Association
|
30
|
|
|
Liebig's services to agricultural chemistry
|
31
|
|
Development of agricultural research in Germany
|
32
|
|
The Rothamsted Experiment Station
|
33
|
|
Sir J. B. Lawes and Sir J. H. Gilbert, the nature and value of their experiments
|
33
|
|
Review of the present state of our knowledge of plant-growth
|
36
|
|
|
Proximate composition of the plant
|
36
|
|
|
Fixation of carbon by plants
|
37
|
|
|
Action of light on plant-growth, Dr. Siemens' experiments
|
38
|
|
|
Source of oxygen and hydrogen in the plant
|
39–40
|
|
|
Source of nitrogen in the plant
|
40
|
|
|
Relation of the free nitrogen to leguminous plants
|
42–44
|
|
|
Relation of nitrogen in organic forms, as ammonia salts, and nitrates to the plant
|
46–50
|
|
|
Nitrification and its conditions
|
51
|
|
|
Ash constituents of the plant
|
53
|
|
|
Methods of research for ascertaining essentialness of ash constituents of plants
|
53
|
|
|
(a) Artificial soils, (b) water-culture
|
53–55
|
|
|
Method in which plants absorb their food-constituents
|
55
|
|
|
Endosmosis
|
55
|
|
|
Retention by soils of plant-food
|
57
|
|
|
Causes of retention by soils of plant-food
|
59
|
|
|
Manuring
|
60
|
|
|
"Field" and "pot" experimentation
|
60
|
|
|
|
PART II.—PRINCIPLES OF MANURING.
|
|
CHAPTER I.—FERTILITY OF THE SOIL.
|
|
What constitutes fertility in a soil
|
65
|
|
I.
|
Physical properties of a soil
|
65
|
|
|
Kinds of soils
|
66
|
|
|
Absorptive power for water of soils
|
67
|
|
|
Absorptive power for water of sand, clay, and humus
|
|
