Chapter 7

Potash of less importance than phosphoric acid 212 Occurrence of potash 213 Felspar and other potash minerals 213 Stassfurt salts 214 Occurrence of saltpetre 215 Occurrence of potash in the soil 215 Potash chiefly in insoluble condition in soils 216 Percentage of potash in plants and plant-ash 216 Occurrence of potash in animal tissue 217 Sources of loss of potash 217 Amount of potash removed in crops 218 Amount of potash removed in milk 218 Potash manures 218

APPENDIX TO CHAPTER VI. NOTE I. Amount of potash in different minerals 220 II. Quantity of potash obtained from 1000 lb. of different kinds of vegetation in the manufacture of potashes 220