xiv tabu; of contents. 



AGRICULT1 RE AND RURAL ECONOMY Continued. 



The Thermal Capacity of the Constituents of Soils Page 531 



The Propagation of the Heal in the Soil 532 



Effect of ( lompactness and Looseness of the Soil upon its Tem- 



perature 532 



The Absorption and Emission of Heat by Soils 533 



The [nfluence of the Color of Soil upon its Temperature 534 



The Influence of Plant-covering and Shade upon the Tempera- 

 ture of the Soil 534 



[nfluence of Exposure on Soil Temperature 535 



Relations of the Soil to Water 535 



Permeability of the Soil to Water 536 



Water-holding Capacity of the Soil 53G 



Evaporation of Water from the Soil 536 



Effect of Loosening the Surface of the Soil upon Evaporation.. 537 



Influence of Hoeing and Rolling the Soil 537 



Experiments on Evaporation of Water from the Soil 538 



1 'hysical Properties of Clay Soils 538 



The Properties of Clay 538 



Inlluence of Clay in the Soil 539 



Reasons for Effects of Lime and Mineral Salts on Clay Soils. . . 510 



Chemical Properties of the Soil. Soil Absorption 540 



Absorption by Exchange of Bases 541 



Absorption without Exchange of Bases 542 



Restoration of Absorptive Power 542 



Absorptive Powers of Different Layers of the Same Soil 542 



Use of Lime and Marl in Soils 543 



Value of Lime in Poor Sandy Soils 544 



Further concerning Chemistry of Soils 544 



Carbonic Acid in Soils 544 



Fertility of Volcanic Soils 545 



Analysis of Soils 545 



Nitrification 546 



Nitrification by Organized Ferments 547 



Experiments on Nitrification by Warrington 547 



Professor Storer on the Ferment Theory of Nitrification 548 



Further Experiments by Schloessing and Miintz 548 



What Kinds of Organisms Cause Nitrification? 548 



Agency of Metallic Oxides in the Formation of Nitrates 549 



IV. Tin-: Plant 549 



( Ihemifltry and Vegetable Physiology 549 



( ihlorophy] and the Formation of Starch 550 



Whal Becomes of the Carbohydrates that are Formed in the 



I <eaves ? 550 



Chemistry of the American Grape 551 



Adda and Sugar in Crapes at Different Periods of Growth 551 



Feeding < lapacities of Plants 552 



i be Feeding Capacity of the Maize-plant 552 



