What is the test for substituting an alternate juror for a deceased juror?

"[I]f at any time after submission of the case to the jury, the juror dies or a juror is discharged by the court because he is ill or otherwise unable to continue, the court may direct the clerk to draw the name of an alternate juror to take the place of the juror who is deceased or discharged. When such a substitution of an alternate juror is made, the court shall instruct the jury to recommence deliberations and shall give the jury such other supplemental instructions as may be appropriate." (Quoted in State v. Corsaro, supra, 526 A.2d at p. 1052.)