-----
Atomic weight -----
Number weight 1506/18 83.66
XENON (Plate XXI, 2 and 4, and Plate XX, 6 and 7) has a peculiarity shared
only by kalon, that _x_ and _y_ are asymmetrical, the centre of one having
three atoms and the centre of the other two. Is this done in order to
preserve the difference of seven from its comrade?

XENON: Six arms of 363 atoms 2178
Central tetrahedra 120
-----
Total 2298
-----
Atomic weight 127.10
Number weight 2298/18 127.66
META-XENON differs from xenon only by the substitution of two _z_'s for _x_
and _y_.

META-XENON: Six arms of 370 atoms 2220
Central tetrahedra 120
-----
Total 2340
-----
Atomic weight -----
Number weight 2340/18 130
KALON (Plate XXI, 3 and 4, and Plate XX, 6 and 7) has a curious cone,
possessing a kind of tail which we have not observed elsewhere; _x_ and _y_
show the same asymmetry as in xenon.

KALON: Six arms of 489 atoms 2934