Electro-Chemical Equivalents 161

chemical equivalents rather as a specimen of a first attempt
than as anything that can supply the want which must very
quickly be felt, of a full and complete tabular account of this
class of bodies. Looking forward to such a table as of extreme
utility (if well constructed) in developing the intimate relation
of ordinary chemical affinity to electrical actions, and identify-
ing the two, not to the imagination merely, but to the conviction
of the senses and a sound judgment, I may be allowed to express
a hope that the endeavour will always be to make it a table of
real, and not hypothetical, electro-chemical equivalents; for
we shall else overrun the facts, and lose all sight and conscious-
ness of the knowledge lying directly in our path.

581. The equivalent numbers do not profess to be exact,
and are taken almost entirely from the chemical results of other
philosophers in whom I could repose more confidence, as to
these points, than in myself.

Oxygen......... 8

Chlorine.........35.5

Iodine.........126

Bromine........78.3

Fluorine.........18.7

Cyanogen.......26

Sulphuric acid . ..40

Hydrogen...... i

Potassium .... 39.2

Sodium........ 23.3

Lithium ....... 10

Barium........ 68.7

Strontium...... 43-8

Calcium........ 20.5

Magnesium..... 12.7

Manganese..... 27.7

Zinc........... 32.5

Tin ........... 57-9

Lead...........103.5

Iron........... 28

Copper ........ 31.6

582. TABLE OF IONS.

Anions.

Selenic acid .....64

Nitric acid ......54

Chloric acid .....75.5

Phosphoric acid ..35.7
Carbonic acid .. . .22

Boracic acid.....24

Acetic acid......51

Cations.

Cadmium...... 55.8

Cerium ...... 46

Cobalt........ 29.5

Nickel ........ 29.5

Antimony..... 64.6?

Bismuth ...... 71

Mercury ......200

Silver ........108

Platina........ 98.6?

Gold.......... (?)

Ammonia ..... 17

Potassa....... 47.2

Tartaric acid.....66

Citric acid.......58

Oxalic acid......36

Sulphur (?) ......16

Selenium (?).....

Sulpho-cyanogen..

Soda .......... 31.3

Lithia ......... 18

Baryta......... 76.7

Strontia........ 51.8

Lime .......... 28.5

Magnesia....... 20.7

Alumina ....... (?)

Protoxides generally.

Quinia .........171.6

Cinchona.......160

Morphia........290

Vegeto-alkalies gener-
ally.

583. This table might be further arranged into groups of
such substances as either act with, or replace, each other.
Thus, for instance, acids and bases act' in relation to each
other; but they do not act in association with oxygen, hydrogen,y acting bodies, remain subject to the continual correction