Lithium.

The lights of the theater were then turned down, and the discourse was continued in darkness; among the most prominent lines visible in the spectrum of the meteorite, Professor Dewar specified magnesium, sodium, and lithium.

You will see," he added, pointing down the second vertical column on the chart, "that gold belongs to the hydrogen grouphydrogen, lithium, sodium, potassium, copper, rubidium, silver, caesium, then two blank spaces for elements yet to be discovered to science, then gold, and finally another unknown element.

Copper to lithium is going backward, so to speak.

It has remained for me to devise this protodyne apparatus by which I can reverse that process of decay and go forward in the table, so to put itcan change lithium into copper and copper into gold.