For some purposes lead is unique and, apparently, irreplaceable. Battery plates may be an example of this.

Unlike the gymnast landing on the firm floor and able to control his balance within fairly wide limits, the diver has little or no control of his position as he enters the water. If he overthrows on entry there is little he can do about it.

His angel, who shall go / Before them in a cloud and pillar of fire.

She was sitting there quietly, then all of a sudden she upped and left.