The disclosure relates to fluorescent lamps and methods of manufacture wherein the mercury is dosed into the lamp in a solid material containing mercury, bismuth, indium and another metal. In one embodiment, the metal is selected from the group consisting of zinc, tin, lead, silver, gold, copper, gallium, titanium, nickel, and manganese. Preferably, the atomic ratio of the indium to the bismuth is in the range of about 0.4:0.6 to 0.7:0.3. The atomic ratio of zinc to the combination indium and bismuth may preferably be in the range of about 0.01:0.99 to 0.20:0.80, and the atomic ratio of mercury to the combination of the indium, bismuth and zinc is preferably in the range of about 0.01:0.99 and 0.15:0.85.