In a column on Sept. 17, I wrote about evidence that Thomas White, the secretary of the Army, was well aware that the Enron division of which he was vice chairman before taking that position, Enron Energy Services, was deliberately and improperly concealing large financial losses. In that column I cited a February 2001 e-mail message that I said was written by Mr. White. Since then Mr. White has said that he does not recall writing such a message, and the authenticity of the message has been questioned. As long as the authenticity of the message remains in doubt, it should be considered unsubstantiated. I erred by citing it in my column.