ALUMINIUM: 6 funnels of 81 atoms 486 Atomic weight 26.91 Number weight 486/18 27.00 GALLIUM (Plate XIII, 2) has two segments in every funnel; in the segment to the left a "cigar" balances a globe, equally six-atomed, in that of the right, and the globes to right and left are four-atomed as against three-atomed. In the next row, the smaller contained globes have six atoms as against four, and the cones have respectively seven and five. By these little additions the left-hand funnel boasts one hundred and twelve atoms as against ninety-eight. GALLIUM: Left segment 112 atoms } Right segment 98 " } = 210 6 funnels of 210 atoms 1260 ---- Atomic weight 69.50 Number weight 1260/18 70.00 INDIUM (Plate XIII, 3) repeats the segments of gallium exactly, save in the substitution of a sixteen-atomed body for the seven-atomed cone of the left-hand segment, and a fourteen-atomed body for the five-atomed corresponding one in gallium. But each funnel now has three segments instead of two; three funnels out of the six contain two segments of type A and one of type B; the remaining three contain two of type B, and one of type A. INDIUM: Segment A 121 atoms Segment B 107 " 3 funnels of 2 A and 1 B ([242 + 107] 3) 1047 3 " " 2 B and 1 A ([214 + 121] 3) 1005 ---- Total 2052 ---- Atomic weight 114.05 Number weight 2052/18 114.00 The corresponding negative group, phosphorus, arsenic, and antimony, run on very similar lines to those we have just examined. [Illustration: PLATE XIV.] PHOSPHORUS (Plate XIV, 1) offers us a very curious arrangement of atoms, which will give some new forms in breaking up. Two segments are in each funnel, in fact the only two of group III _a_ which do not show this arrangement, or a modification thereof, are aluminium and arsenic.