Jenkin, William, discovery of the "extra current" by, 268.
Joule and Thomson's determination of the heat absorbed by air in
expanding, 324.
Joule, Dr., establishment of mechanical theory of heat by, 193, 324.
Joule's law, 324;
proof that heat and energy are equivalent, 324;
determination of the mechanical equivalent of heat, 325.
Junto Club, formation of the, 51.