title: Erratum.
abstract: In my communication "Toxicity and the Chemical Properties of Ions" in the August 19th issue of Science, the ionic field was printed as p((1/2)) (p. 194, second column, third line from bottom). It should be r((1/2)), i.e. the reciprocal of the square of the ionic radius.
authors.forename: W
authors.initials: W
authors.lastname: Seifriz