See Ashes.

These, which are the basis of charred turf, now becoming so usual a manure, are, according to M. Sprengel, thus constituted: -

Silica........93.10

Alumina .................

1.35

Oxide of Iron .................

1.73

-------manganese ..................

0.32

Lime ............................

0.62

Magnesia ....................

0.33

Potash, combined with sulphuric acid ....................

0.38

Common salt ...................

0.08

Sulphuric acid, combined with potash and lime ....

1.70

Phosphoric acid, combined with lime and magnesia .

0.39