410 An Account of some ^Experiments 



Exp. 1 . A platina and a gold wire being thus connected, and 

 introduced into the electrical circuit, the platina was instantly 

 ignited, the gold remained unaffected. 



Exp. 2. A similar arrangement of gold and silver wires. 

 The gold was ignited, the silver not. 



Exp. 3. The same wiih gold and copper. No perceptible 

 difference in the state of ignition ; both metals were heated red. 



Exp. 4. Gold and iron. The iron was ignited; the gold 

 unchanged. 



Exp. 5. Platina and iron. The i-on ignited instantly at the 

 point of contact next the pole of the battery. Then the platina 

 became ignited through its whole extent. After this the iron 

 became more intensely heated than the j)latina, and the ignition 

 of the latter decreased. 



Exp. 6. Platina and zinc. The platina was ignited ; the 

 zinc was not ; but melted at the point of contact. In a subse- 

 quent experiment, the zinc did not melt ; but the platina ignited 

 as before. 



Exp. 7. Zinc and iron. The iron was ignited; the zinc 

 bore the heat witiiout fusing. 



Exp. 8. Lead and platiua. The lead fused at the point of 

 contr.ct. 



Exp. 9. Tin and platina. Tlie tin fused at the point of 

 contact. No ignition of either wire took place in the two last 

 experiments. 



Exp. 10. Zinc and silver. The zinc was ignited before it 

 melted : the silver was not ignited. 



The results in every case were the same to whichever pole 

 of the battery either wire was presented. I varied these experi- 

 ments by introducing several alternations of different wires con- 

 tinuously connected into the circuit, and obtained in every in- 

 stance analogous results. Thus 



Exp. 1 1. Alternations of platina and silver, three times re- 

 peated : all the platina '.vires were ignited, and none of the silver. 



JE.rp. 12. One zinc wire between two platina: both the 

 platina wires were ignited, the zinc not. 



I£xp. \3. One iron between two platina. Both the latter 

 first ignited ; then the iron, which soon became most heated, 

 and fused. 



It is unnecessary to enter into a further detail of these experi- 

 ments ; it will be sufficient to say generally, that when wires of 

 .several different metals were introduced at once into the circuit, 

 the order of their ignition was precisely that of the former ex- 

 periments. In one experiment with copper and gold, the copper 

 was decidedly most heated. 



1 feel some difficulty in attempting an explanation of the pre- 

 ceding 



