51.   Investigators are still analyzing spores found in a letter that was mailed to Sen. Patrick Leahy but never delivered.

52.   No anthrax spores were found in the envelope, the Interfax news agency said, but a parliamentary spokeswoman said sanitary experts would have final conclusions on Thursday.

53.   Nineteen buildings including and surrounding the Capitol have undergone environmental surveys and anthrax spores have been found in four of them, Nichols said.

54.   Spores were also found in the offices of Rep. Elijah E. Cummings of Maryland, in the Longworth House office building.

55.   Spores also were found in the office of Rep. Elijah E. Cummings of Maryland in the Longworth House office building, said Lt. Dan Nichols of the Capitol Police.

56.   Spores were found in yet more government buildings, this time in four Food and Drug Administration mailrooms near Washington.

57.   Spores are found in yet more government buildings, this time in four Food and Drug Administration mailrooms near Washington.

58.   Spores were found in the offices of Sens. Larry Craig of Idaho, Bob Graham of Florida and Dianne Feinstein of California.

59.   The FDA said Thursday that preliminary tests found anthrax spores in mailrooms of four of its five buildings in Rockville, Maryland, where mail is processed.

60.   The FDA said Thursday that preliminary tests found spores in mailrooms of four of its five buildings in Rockville, Maryland.