Chapter XXIX: Appendix: To Chapter VI

NOTE I. (p. 215).

AMOUNT OF POTASH IN DIFFERENT MINERALS.

Felspars--
Percentage of potash.
(_a_) Orthoclase { 9.11 10.28 11.07 12.12 12.47
{ 13.49 14.35 15.21 16.7
(_b_) Oligoclase 0.50
(_c_) Labradorite 0.33
Mica { 5.61 6.20 7.23 8.26 8.95
{ 9.00 10.25 12.40 13.15
Amphibole 0.25 2.96
Pyroxene 0.34 2.48
Leucite 13.60 18.61
Zeolites 0.30 9.35 0.98 4.93

Stassfurt potash salts-- Per cent.
(_a_) Polyhallite, _potassium sulphate_ 28
(_b_) Karnallite (KCl.MgCl_{2}6H_{20}), _potassium chloride_ 24 to 27
(_c_) Sylvin, pure _potassium chloride_.
(_d_) Kainit (K_{2}SO_{4}MgSO_{4}MgCl_{2}6H_{2}O), _potassium
sulphate_ 32
(_e_) Schoenite (K_{2}SO_{4}, MgSO_{4}, 6H_{2}O), pure
_potassium magnesium sulphate_.

NOTE II. (p. 217).

The quantity of potash obtainable from various plants in the manufacture of potashes on a large scale is illustrated by the following statements. 1000 lb. of the following vegetative products yield the following quantities of potashes:--

lb. Old spruce-wood 1/2 Old poplar-wood 3/4 Old oak-wood 1-1/2 Corn-stalks 17-1/2 Bean-stalks 20 Grape-vine twigs 40

(Storer, 'Agricultural Chemistry,' vol. ii. p. 108.)