"The proper fixed alkalies are of two kinds, the vegetable or ', and the mineral or soda; the latter is found often native in immense quantities being the basis of rock salt, and is also the principal saline residue of many plants growing on the sea shore; and the former is contained in, and almost entirely procured from, the ashes of vegetables in general, not growing contiguous to the sea. Under the articles Potash and Soda, and Carbonat of Potash and Soda, these most important Salts are fully described."