INSTRUMENTAL a.
dative, and in Latin into the ablative. In Old English it was a separate case, but has disappeared, leaving only a few anomalous forms. Instrumental errors, those errors in instrumental measurements, etc., which arise, exclusively from want of mathematical accuracy in an instrument.
IRON n.
us scale in three principal forms; viz., cast iron, steel, and wrought iron. Iron usually appears dark brown, from oxidation or impurity, but when pure, or an fresh surface, is a gray or white metal. It is easily oxidized (rusted) by moisture, and is attacked by many corrosive agents. Symbol Fe (Latin Ferrum). Atomic w…