58 Mr Murray on the unequal Distribution of Caloric 
In the preceding experiments, the plates of zinc having been 
much corroded, might be expected to affect the results, and 
render them somewhat equivocal. The phenomena, however, 
seemed to indicate a gradual declension of temperature from the 
positive to the negative pole. It is curious, too, that the alter- 
nate troughs singularly coincide. It was also evident, that 
there obtained a maximum near the central region of the indi- 
vidual trough, with a gradual declension in each, pointing in the 
direction of the negative pole. These facts prove, that an une- 
qual distribution of temperature is associated with the produc- 
tion of galvanic phenomena. 
The plates were renewed in the experiments which succeed. 
On the 18th September 1823, temperature of water 62°, the 
same strength of acid was employed. From 14 to 15 inches of 
platinum-wire, T i 5 th of an inch diameter, were made white hot . 
In the first series, the temperature was taken before the plates 
were removed , and when the action had been reduced to the ig- 
nition of a few inches of the wire. It commences with the cop- 
per or negative cell. 
Is2 Trough. 2d Trough. 
( Copper end.) — Last cell, 101° F. Last cell, 125° F. 
Middle, 106 Middle, 140 
First, 112 First, 135 
3 d Trough. 
Last cell, 138° F. 
Middle, 141 
First, 138 
4th Trough. 
Last cell, 136° F. 
Middle, 142 
First, 142 ( Zinc or positive end. ) 
It appears from the foregoing, that the minimum of tem- 
perature in the aggregate troughs is at the copper or negative 
limit, and the maximum at the positive or zinc termination. 
In three of these troughs the maximum of the individual one is 
still maintained toward the centre. 
When the plates were removed, the following was the exhi- 
bition of temperature. 
Trough. 
2d Trough. 
3d Trough. 
4th Trough. 
( Copper plate. ) 1 0 1 ° F. 
123° F. 
128° F. 
128° F. 
106 
125 
129 
129 
109 
127 
130 
131 
110 
129 
131 
133 
111 
131 
132 
134 
* 112 
133 
133 
134 
112 
134 
133 
133 
113 
133 
131 
133 
113 
131 
130 
132 
110 
129 
129 
132 ( Zinc plate.) 
