CONTENTS. XXV 



APPENDIX TO CHAPTER XIII. 

 NOTE 



I. The formulae, and molecular and percentage composition, 



of the different phosphates ...... 398 



II. Reactions of sulphuric acid and phosphate of lime . . 398 



III. Table for conversion of soluble phosphate into insoluble 



phosphate 399 



IV. Action of iron and alumina in causing reversion . . 399 

 V. Relative trade values of phosphoric acid in different 



manures ......... 400 



CHAPTER XIV. THOMAS-PHOSPHATE OR 

 BASIC SLAG. 



Its manufacture ......... 401 



Not at first used 403 



Discovery of its value as a manure 403 



Composition of basic slag ....... 404 



Processes for preparing slag ....... 406 



Solubility of basic slag . . . . . . . .408 



Darmstadt experiments with basic slag . . . . . 410 



Results of other experiments . . . . . . .413 



Soils most suited for slag . . . . . . .414 



Rate of application . . . . . . . . .414 



Method of application . . . . . . . .416 



APPENDIX TO CHAPTER XIV. 



Analysis of basic slag . . . . . . . .417 



CHAPTER XV. POTASSIC MANURES. 



Relative importance . . . . . . . .418 



Scottish soils supplied with potash . . . . . .419 



Sources of potassic manures . . . . . . .419 



Stassfurt potash salts . . . . . . . .420 



Relative merits of sulphate and muriate of potash . . .421 

 Application of potash manures ....... 422 



Soils and crops suited for potash manures .... 423 



Rate of application ......... 423 



