CADMIUM: 3 segments of 164 atoms = 492 4 funnels of 492 atoms 1968 Central body 48 ----- Total 2016 ----- Atomic weight 111.60 Number weight 2016/18 112.00 The corresponding negative group is headed by [Illustration: PLATE X.] SULPHUR (Plate X, 1), which, like magnesium, has no central globe, and consists simply of the zinc funnels, much less compressed than zinc but the same in composition. SULPHUR: 4 funnels of 144 atoms 576 Atomic weight 31.82 Number weight 576/18 32.00 SELENIUM (Plate X, 2) is distinguished by the exquisite peculiarity, already noticed, of a quivering star, floating across the mouth of each funnel, and dancing violently when a ray of light falls upon it. It is known that the conductivity of selenium varies with the intensity of the light falling upon it, and it may be that the star is in some way connected with its conductivity. It will be seen that the star is a very complicated body, and in each of its six points the two five-atomed spheres revolve round the seven-atomed cone. The bodies in the funnels resemble those in magnesium, but a reversed image of the top one is interposed between itself and the small duad, and each pair has its own enclosure. The central globe is the same as that of zinc. SELENIUM: 4 funnels of 198 atoms 792 4 stars of 153 atoms 612 Central globe 18 ----- Total 1422 ----- Atomic weight 78.58 Number weight 1422/18 79.00 TELLURIUM (Plate X, 3), it will be seen, closely resembles cadmium, and has three cylindrical segments--of which one is figured--making up the funnel. The contained bodies in the pillars run three, four, five, four, three, two, instead of starting with two; and a quartet replaces a duad in the globes above. The central cross only differs from that of cadmium in having a seven-atomed instead of a four-atomed centre. So close a similarity is striking. TELLURIUM: 3 segments of 181 atoms = 543 4 funnels of 543 atoms 2172 Central body 51 ----- Total 2223 ----- Atomic weight 126.64 Number weight 2223/18 123.50 * * * * * V.