TO POSE POLARIZED BROMIDES: while necessity is the mother of invention, one really cannot make a silk purse out of a sow's ear. In other words, there is an extensive array of paraphernalia associated with the metals analyst's work for which even the most innovative substitution simply will not do. It behooves the analyst, therefore, to know his or her tools and materials very well, to have them on hand, and to select among them judiciously.