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
       Central tetrahedra 120
                                      ——­
                            Total 3054
                                      ——­
       Atomic weight ——­
       Number weight 3054/18 169.66
META-KALON again substitutes two z’s for x and y.

META-KALON:  Six arms of 496 atoms 2976
            Central tetrahedra 120
                                            ——­
                            Total 3096
                                            ——­
            Atomic weight ——­
            Number weight 3096/18 172
Only a few atoms of kalon and meta-kalon have been found in the air of a
fair-sized room.

It does not seem worth while to break up these elements, for their component parts are so familiar.  The complicated groups—­a 110, b 63 and c 120—­have all been fully dealt with in preceding pages.

* * * * *

There remains now only radium, of the elements which we have, so far, examined, and that will be now described and will bring to an end this series of observations.  A piece of close and detailed work of this kind, although necessarily imperfect, will have its value in the future, when science along its own lines shall have confirmed these researches.

It will have been observed that our weights, obtained by counting, are almost invariably slightly in excess of the orthodox ones:  it is interesting that in the latest report of the International Commission (November 13, 1907), printed in the Proceedings of the Chemical Society of London, Vol.  XXIV, No. 33, and issued on January 25, 1908, the weight of hydrogen is now taken at 1.008 instead of at 1.  This would slightly raise all the orthodox weights; thus aluminium rises from 26.91 to 27.1, antimony from 119.34 to 120.2, and so on.

* * * * *

XI.

RADIUM.

[Illustration:  PLATE XXII.]