"The original application of the term alkali (which is of Arabian origin) was to express the acrid saline residue left in the ashes of the plant kali, after its combustion in open air. This was also very early known to the Greeks and Romans; by the latter termed, lixivial, which term is still retained, lixivium, or ley, meaning properly the soluble salt extracted out of vegetable ashes by the addition of water. From the circumstance of the ashes being the fixed or unvolatilized part of the plant, the rest having been dissipated by the combustion, the lixiviary salt was also called fixed alkali, a term still in universal use."