1 ELECTRO CHEMISTRY. 



potassium into another. In every respect the ex- 

 periment was conducted as before, and with precisely 

 the same result. 



11. Exp. 3.- January 2, 1858. 



The iodide of potassium decomposed by elec- 

 tricity, of which the positive electricity was derived 

 from oxygen, and the negative electricity from potas- 

 sium. 



Two grains of the chlorate of potassa were intro- 

 duced into one of the tubes, from which oxygen by 

 heat was evolved, and an equivalent quantity of 

 potassium into the other. In the decomposition of 

 the solution in the bent tube, the iodine was first 

 made apparent in the limb of the tube into which the 

 wire from the oxygen was introduced, which indicates 

 that the positive electricity was derived from the 

 oxygen, and consequently the negative electricity 

 from the metal. 



12. Exp. 4. January 16, 1858. 



A solution of the iodide of potassium was decom- 

 posed by electricity, of which the positive electricity 

 was derived from iodine, and the negative electricity 

 from potassium. 



Six grains of iodine were introduced into one of 

 the tubes deposited in the tray, and two grains of 

 potassium in the other. When the tray was brought 



