Yesterday's opening testimony at the trial of Leon J. Kamin '49 followed a fruitless first day which ended in a mistrial and a waiver by Kamin of his right to a trial by jury. The mistrial was caused by loud applause for Senator Joseph R. McCarthy.

The Wisconsin Senator appeared in the corridors outside Judge Bailey Aldrich's courtroom several times Tuesday morning while the jury was being selected. He was applauded vigorously by spectators each time.

It was not until after the jury had been chosen and the court recessed for lunch that a motion for a mistrial was considered. Apparently, Judge Aldrich and the defense lawyers did not learn of the incident until that time.

Asks Fair Trial

After conferences between the judge, Kamin, and lawyers for both sides, the court met at 3:45 p.m. after a recess of nearly three hours. Kamin's attorney, Calvin P. Bartlett, immediately moved for a mistrial and the motion was granted after Kamin asked for it personally.

Aldrich explained that the defense felt its right to a fair trial before the newly selected jury would be "gravely prejudiced" by the information that Senator McCarthy had been applauded.

Aldrich said he did not suggest that McCarthy had invited applause but that "nothing is more foreign to a trial than for a witness even to appear to be engaged in a popularity contest." He thanked the jurors for their "day spent to no purpose," and dismissed them.

The new trial, without a jury, is considered more favorable to Kamin. Judge Aldrich will now hear questions of fact and rule on legal matters.

Judge Aldrich would have had a large role in determining the course of the case even had the jury remained, since much of the evidence to be introduced was to relate only to legal questions.