On page 1702 of the June issue, the third paragraph of the article "Lithium in Manic-Depressive Illness," by R. J. Kerry, M.R.C.S., L.R.C.P., D.P.M., and G. Owen, M.B., M.C. Path., contains an error. The word "lithium" should be replaced by "tritium" and the corrected sentence should read "Samples of urine were collected before a dose of tritium was given. . . ."