LOWELL | In the Middle Ages, it was called the "Black Death."

It was at a time when Europe was ravaged by three strains of the disease, the bubonic, pneumonic and septicemic plagues. All three were deadly, and historians calculated that one-fourth of the population of Europe, or as many as 25,000,000 people, died during the great epidemic.

Two Lowell High School teachers, Terry Brandush and Chris Werling, who teach nearly 100 students in a humanities class, decided to conduct a schoolwide experiment Thursday based on the topic of plagues and the rate at which disease could spread and become an epidemic.

The two teachers used half sheets of paper that told recipients which plague they had been infected with, and instructed them to write their names on the back of the paper and pass it on.

The experiment began at 8:45 a.m. Students handed slips to teachers, and teachers handed slips to students during lunch and passing periods.

By the end of the day, the two teachers had a handful of pink, hot pink and gray sheets of paper in their hands, and handfuls of sheets were stuffed in their mailboxes.

Freshman Ally Clark, 14, got the "bug" twice.

"I thought the experiment was really kind of cool," she said, while sitting in her art class with teacher Thomas Sufana.

"I passed it to a friend the first time I got it. The second time, I gave it to Mr. Sufana," she said.

Sufana, who was at his desk, sort of threw up his hands and smiled when he acknowledged that he now had "the plague."

Brandush and Werling said their goal was to make students aware of how serious disease was in the Middle Ages and how quickly it could be transmitted. They told students those diseases are now curable. They also promised to provide information on the number of teachers and students who "got the plague" during the day.