LITHIUM (Plate IV, 2 and Plate XIX, 1) is a striking and beautiful form, with its upright cone, or spike, its eight radiating petals (_x_) at the base of the cone, and the plate-like support in the centre of which is a globe, on which the spike rests. The spike revolves swiftly on its axis, carrying the petals with it; the plate revolves equally swiftly in the opposite direction. Within the spike are two globes and a long ovoid; the spheres within the globe revolve as a cross; within the ovoid are four spheres containing atoms arranged on tetrahedra, and a central sphere with an axis of three atoms surrounded by a spinning wheel of six. LITHIUM: Spike of 63 atoms 63 8 petals of 6 atoms 48 Central globe of 16 atoms 16 ---- Total 127 ---- Atomic weight 6.98 Number weight 127/18 7.05 POTASSIUM (Plate XIX, 2) consists of nine radiating lithium spikes, but has not petals; its central globe contains one hundred and thirty-four atoms, consisting of the "nitrogen balloon," encircled by six four-atomed spheres. POTASSIUM: 9 bars of 63 atoms 567 Central globe 134 ---- Total 701 ---- Atomic weight 38.94 Number weight 701/18 38.85 (The weight, as determined by Richards [_Nature_, July 18, 1907] is 39.114.) RUBIDIUM: (Plate XIX, 3) adds an ovoid, containing three spheres--two triplets and a sextet--to the lithium spike, of which it has sixteen, and its central globe is composed of three "balloons." RUBIDIUM: 16 spikes of 75 atoms 1200 Central globe 330 ---- Total 1530 ---- Atomic weight 84.85 Number weight 1530/18 85.00 The corresponding negative group consists only of fluorine and manganese, so far as our investigations have gone. FLUORINE (Plate IV, 3, and Plate XVII, 1) is a most peculiar looking object like a projectile, and gives one the impression of being ready to shoot off on the smallest provocation. The eight spikes, reversed funnels, coming to a point, are probably responsible for this warlike appearance. The remainder of the body is occupied by two "balloons."