5·0|{Cobalt     58·7|
                 |                  |              |{Nickel     58·6|
                 |                  |              |                |
                 |                  |              |{Ruthenium 101·6|
  Niobium    94·0|Molybdenum    95·7|?        100·0|{Rhodium   103·0|
                 |                  |              |{Palladium 106·3|
                 |                  |              |                |
  Neodymium 140·8|Praseodymium 143·6|Samarium 150·0|? 152, 153, 154 |
                 |                  |              |                |
                 |                  |              |{Osmium    191·3|
  Tantalum  182·5|Tungsten     184·0|?        190·0|{Iridium   193·0|
                 |                  |              |{Platinum  194·3|
                 |                  |              |                |
  ?              |Uranium      240·0|?        244·0|                |
  ---------------+------------------+--------------+----------------+

The elements in the first column all agree in that they are white soft
substances, with metallic lustre, but tarnish rapidly in air, owing to
the action of water-vapour; they are all violently attacked by water,
and they are without exception monads, that is, they replace hydrogen
in its compounds atom for atom. The elements in column two are also all
white metals, attacked by water with more or less ease; but in their
case one atom replaces two atoms of hydrogen, whence they are called
dyads, or bivalent elements (worth two). And so on with the other
columns. All elements in vertical columns exhibit chemical similarity,
and, indeed, are often strikingly like in properties.

The subdivision, produced by folding the loose page, is intended
to show that the elements represented on it have a double set of
resemblances. But there are various anomalous and inexplicable
phenomena still attached to this arrangement of elements. For example,
copper, although it replaces one atom of hydrogen in some of its
compounds, a