Deputy Chief Phil Lemire said crews inspecting a former private hospital at 945 Middlesex St. came across the rusted old containers in the basement around 3 p.m.
A state police bomb squad and an agent from the federal Bureau of Alcohol, Tobacco and Firearms were called in to help dispose of the containers. The city's hazardous-materials coordinator was also called in.
The aged ether can be set off by friction, heat or even direct light, Lemire said.
Members of the bomb squad donned protective suits, including flak jackets and oxygen masks, and secured the containers in "frag-bags," so they could be removed from the building.
"Frag-bags" are specially designed bags that could contain the force of a small- to medium-sized explosion.
The bags were then buried in sand in the back of a Department of Public Works truck, escorted by police and fire vehicles, and hauled to the Lowell landfill, where the bomb squad set them off.
Lemire said the transit was safe and that the bags were buried so that even if an explosion escaped the bags, the sand would direct it straight up into the air.
A portion of Middlesex Street was closed for a couple of hours until crews removed the containers around 6 p.m. Crews wrapped up at the landfill about 8 p.m.
