These pretty blue bottles were not decorative. Their fragile glass was designed to break easily when thrown…at a fire! They were called “glass hand grenades” and were made ca. 1877 by the Harden Hand Grenade Company of Chicago. They were filled with carbon tetrachloride (now a known carcinogen) and sealed with a cork and then cemented. (The cement would prevent the noxious liquid from escaping if the cork shrank.) Grenades such as these were plentiful in Dover factories, within easy reach of mill workers. If a fire started, employees would throw them at the base of the blaze and a fire-suppressant gas would be instantly released. They were used until about 1910.