339 
the Decomposition of the Earths , &c. 
constructed in the Laboratory of the Royal Institution, and con- 
sisting of five hundred pairs of double plates of six inches 
square. 
When I attempted to obtain amalgams with this appa- 
ratus, the transmitting wires being of platina, of about ■£- of an 
inch in diameter ; the heat generated was so great as to burn 
both the mercury and basis of the amalgam at the moment 
of its formation ; and when by extending the surfaces of the 
conductors, this power of ignition was modified, yet still the 
amalgam was only produced in thin films, and I could not 
obtain globules sufficiently large to submit to distillation. 
When the transmitting wires were of iron of the same thick- 
ness, the iron acquired the temperature of ignition, and com- 
bined with the bases of the earths in preference to the mercury, 
and metallic alloys of a dark grey colour were obtained, which 
acted on water with the evolution of hydrogene, and were 
converted into oxide of iron, and alkaline earths. 
Whilst I was engaged in these experiments, in the beginning 
of June, I received a letter from Professor Berzelius of Stock- 
holm, in which he informed me that in conjunction with Dr. 
Pontin, he had succeeded in decomposing barytes and lime, 
by negatively electrifying mercury in contact with them, and 
that in this way he had obtained amalgams of the metals of 
these earths. 
I immediately repeated these operations with perfect suc- 
cess ; a globule of mercury, electrified by the power of the 
battery of 500, weakly charged, was made to act upon a 
surface of slightly moistened barytes, fixed upon a plate of 
platina. The mercury gradually became less fluid, and after 
a few minutes was found covered with a white film of barytes; 
X x 2 
