408 
Sir Humphry Davy on the relations of 
metal is one of the conditions of continued electrical action ; 
and the cessation of the power of De Luc's or Zamboni’s 
piles, is always connected with the tarnish of the imperfect 
metal employed in them. 
Having published many years ago tables of the electro- 
chemical relations of metals, which have been copied into 
many elementary books, I think it proper to give them here 
in a corrected form with some additions, and the differences 
dependent upon the nature of the menstruum. The metal 
mentioned first is positive to all those below it in the scale. 
With common acids . 
Potassium and its amalgams ; barium and its amalgams ; 
amalgam of zinc ; zinc ; amalgam of ammonium ( ? ) ; cad- 
mium, tin, iron, bismuth, antimony (?), lead, copper, silver, 
palladium, tellurium, gold, charcoal, platinum, iridium, 
rhodium. 
With alkaline solutions. 
The alkaline metals and their amalgams : zinc, tin, lead, 
copper, iron, silver, palladium, gold, platinum, &c. 
With solutions of hydro-sulphurets. 
Zinc, tin, copper, iron, bismuth, silver, platinum, palla*- 
dium, gold, charcoal. 
VII. On the accumulation of electricity , and the chemical changes 
it occasions in Voltaic arrangements . 
In the view of electro-motion adopted by the illustrious 
inventor of the pile, the metals were considered as the only 
