Fluorescent tube with mercury amalgam on tube wall

Claim 1

IN A FLUORESCENT TUBE OF THE CHARACTER DESCRIBED, IN COMBINATION, A TUBE HAVING AN INNER SURFACE; INCANDESCENT ELECTRODES LOCATED IN SAID TUBE; FLUORESCENT MATERIAL COVERING AT LEAST THE MAJOR PORTION OF THE INNER SURFACE OF SAID TUBE; A RARE GAS LOCATED IN SAID TUBE; AND A BODY OF ONE AMALGAM SELECTED FROM THE GROUP CONSISTING OF TIN AMALGAM CONSISTING OF TIN AND UP TO 10 ATOMIC PERCENT OF MERCURY, GOLD AMALGAM CONSISTING OF GOLD AND UP TO 14 ATOMIC PERCENT OF MERCURY, SILVER AMALGAM CONSISTING OF SILVER AND UP TO 14 ATOMIC PERCENT OF MERCURY, AND POTASSIUM AMALGAM CONSISTING OF MERCURY AND BETWEEN 25 AND 33 ATOMIC PERCENT OF POTASSIUM, ADHERING TO A RELATIVELY SMALL PORTION OF SAID INNER SURFACE OF SAID TUBE SPACED FROM SAID ELECTRODES, RESPECTIVELY, AT A DISTANCE OF BETWEEN ABOUT 8 AND 12 CM., THE MERCURY CONTENT OF SAID BODY OF AMALGAM BEING SUCH THAT A TEMPERATURE OF UP TO ABOUT 80* C. THE MERCURY VAPOR PRESSURE OF SAID AMALGAM WILL NOT EXCEED ABOUT 0.01 MM. HG.