developed between Metals and fused Salts. 4S5 



the iodide of potassium, and laid on a platina plate, which 

 was in metallic connection with one of the platina wires used 

 in the previous experiments. The extremity of the other pla- 

 tina wire in contact with the globule, was applied to the sur- 

 face of the bibulous paper, and the flame of the lamp was so 

 directed, that the latter was the colder of the wires between 

 which the globule of borax or carbonate of soda was fused. 

 The platina plate in this arrangement therefore constituted 

 the negative pole, and the extremity of the wire applied to 

 the bibulous paper, the positive pole. Accordingly, when the 

 circuit was completed, an abundant deposition of iodine oc- 

 curred beneath the platina wire. When a similar wire of 

 platina was substituted for the plate on the negative side, the 

 effect was either none or scarcely perceptible. 



A compound arrangement was next formed by placing a 

 series of platina wires on supports, in the same horizontal line, 

 and fusing between their adjacent extremities small globules 

 of borax. The globules and wires were exactly similar to 

 those that are used in blowpipe experiments. A spirit-lamp 

 was applied to each globule, so as to heat unequally the 

 wires in contact with it; and the corresponding extremity of 

 each wire being preserved at the higher temperature, the cur- 

 rent was transmitted in the same direction through the whole 

 series. By connecting the extremities of four cells of this ar- 

 rangement with an apparatus for decomposing water, in which 

 the opposite poles consisted of a thick platina wire and a 

 guarded platini point (both being immersed in dilute sul- 

 phuric acid), very minute bubbles of gas soon appeared at 

 the guarded point, and slowly separating from it ascended 

 through the liquid. They were obtained in whichever di- 

 rection the current was passed, but rather more abundantly 

 when the point was negative and the wire positive. With only 

 two cells, similar bubbles formed in a visible manner on the 

 guarded point, but in such exceedingly small quantity that 

 they did not separate from it. With an arrangement con- 

 taining 20 cells, a doubtful sensation was communicated to 

 the tongue when the poles were applied to 't ; but no spark 

 was visible, although the current was passed through a helix 

 of copper wire surrounding a bar of iron, and the contact was 

 broken with great rapidity by means of a revolving apparatus. 

 It is necessary to observe, however, that the lamps were unpro- 

 tected, and that it was impossible to render the flames of such 

 a number of spirit-lamps burning near each other, so steady 

 as to heat at the same moment, in the required manner, all 

 the globules and wires. With an enlarged and more perfect 

 form of apparatus, there can be little doubt that a spark might 

 be obtained. 



3K2 



