The Idaho capital building was evacuated for about three hours yesterday. Authorities say a suspicious white powdery substance found in a letter mailed to the Idaho Attorney General's Office was nothing more than aspirin. The envelope was opened by a state employee and inside there was a white substance and a note.  The note said the envelope contained anthrax and it also had a bomb threat. A hazmat team was called to the Capitol to test the substance. The testing took more than an hour. Meanwhile, the Capitol building was evacuated. Gov. Butch Otter was in the building but was evacuated with other employees. the FBI and Idaho State Police are investigating the incident.