It also turns out that some scientists are proposing to deploy guinea pigs, rabbits and mice in the nation's homes and public buildings as alarms to detect airborne anthrax.

At the office, we demand X-ray scanners and other high-tech devices that might detect explosives or anthrax.

A blood sample was given to the Pennsylvania Department of Health, which detected anthrax in its own test on Tuesday and promptly notified federal and New York City authorities.

Those tests detected anthrax, and the results were reported to Tommy Thompson, secretary for the federal Department of Health and Human Services, at 3:25 a.m. yesterday.

But the monitors detect only anthrax, which sickened postal workers in 2001.

There he declared that new technologies to detect anthrax, sniff biological attacks in buildings and help contain panic after an attack would help win "the defining conflict of the 21st century."

The letter to Mr. Daschle was quickly tested in an Army laboratory, which detected anthrax.

"The mediastinal X-ray findings were immediate clues that something unusual was going on," she said, and led to more extensive testing that detected anthrax in the patients.

Scientists have developed a new laser technique that could detect anthrax in real time.

Dr. Imre is adapting the machine to detect anthrax down to a single spore.