Deputy Solicitor General Friedman argued the cause for the United States. With him on the briefs were Solicitor General Griswold, Assistant Attorney General McLaren, Harry R. Sachse, Howard E. Shapiro, and Harry G. Sklarsky.

John E. F. Wood argued the cause for respondents. With him on the brief for Chas. Pfizer & Co., Inc., were Judson A. Parsons, Jr., J. Paul McGrath, Paul Sherman, and Arthur G. Connolly. Roy W. McDonald, Ralstone R. Irvine, and Richard Y. Holcomb filed a brief for respondent American Cyanamid Co. Merrell E. Clark, Jr., and Henry J. Zafian filed a brief for respondent Bristol-Myers Co.

PER CURIAM.

The judgment is affirmed by an equally divided Court.

MR. JUSTICE STEWART, MR. JUSTICE WHITE, and MR. JUSTICE MARSHALL took no part in the consideration or decision of this case.