[A] The term quantity in electricity is perhaps sufficiently definite as to sense; the term intensity is more difficult to define strictly.  I am using the terms in their ordinary and accepted meaning.

Table of the experimental Effects common to the Electricities derived from different Sources[A].

Table headings

A:  Physiological Effects
B:  Magnetic Deflection. 
C:  Magnets made. 
D:  Spark. 
E:  Heating Power. 
F:  True chemical Action. 
G:  Attraction and Repulsion. 
H:  Discharge by Hot Air. _____________________________
____________________________
| | | | | | | | | |
| | A | B | C | D | E | F | G | H |
|_________________________|___|___|___|___|___|___|___|___|<
br> | | | | | | | | | |
| 1.  Voltaic electricity | X | X | X | X | X | X | X | X |
|_________________________|___|___|___|___|___|___|___|___|<
br> | | | | | | | | | |
| 2.  Common electricity | X | X | X | X | X | X | X | X |
|_________________________|___|___|___|___|___|___|___|___|<
br> | | | | | | | | | |
| 3.  Magneto-Electricity | X | X | X | X | X | X | X | |
|_________________________|___|___|___|___|___|___|___|___|<
br> | | | | | | | | | |
| 4.  Thermo-Electricity | X | X | + | + | + | + | | |
|_________________________|___|___|___|___|___|___|___|___|<
br> | | | | | | | | | |
| 5.  Animal Electricity | X | X | X | + | + | X | | |
|_________________________|___|___|___|___|___|___|___|___|<
/i>

[A] Many of the spaces in this table originally left blank may now be filled.  Thus with thermo-electricity, Botto made magnets and obtained polar chemical decomposition:  Antinori produced the spark; and if it has not been done before, Mr. Watkins has recently heated a wire in Harris’s thermo-electrometer.  In respect to animal electricity, Matteucci and Linari have obtained the spark from the torpedo, and I have recently procured it from the gymnotus:  Dr. Davy has observed the heating power of the current from the torpedo.  I have therefore filled up these spaces with crosses, in a different position to the others originally in the table.  There remain but five spaces unmarked, two under attraction and repulsion, and three under discharge by hot air; and though these effects have not yet been obtained, it is a necessary conclusion that they must be possible, since the spark corresponding to them has been procured.  For when a discharge across cold air can occur, that intensity which is the only essential additional requisite for the other effects must be present.—­Dec. 13 1838.

S 8. Relation by Measure of common and voltaic Electricity.[A]