322 Trof, Cnmming on some anomalous Appearances [Nov, 



If the experiment be made by dipping wires, not previously 

 connected, m boiling mercury, the deviation in the first instance 

 depends, in some cases, uuon the order in which they are 

 immersed. I have obsfetvea this appearance more especially 

 when one of the wires is copper, zinc, or brass. The results 

 w ere : 



r Copper last; negative, then slightly 

 Copper with gold I positive. 



L Gold last; positive* 

 . silver I Copper last ; negative. 



\ Silver last ; positive, then negative. 



r Copper last ; negative. 

 \ Zinc last ; positive, 



\ Zinc last ; positive, then negative. 



r Copper last; negative slightly, then 

 positive. 

 Brass last ; positive. 



brass , . . . < positive. 



(Copper last ; negative. 

 r ■ - ^ 



— — — plumbago. < Plumbago last; positive, then nega- 



L tive. 



Copper with platina or tin was positive, with iron negative in 

 both cases. 



7\r^c with silver / ^^"^^ ^^^* ' negative, then positive. 



Zmc AMtti silver -^ g.j^^^. j^^^ . positive. 



r Zinc last; negative. 

 ■ ■ — — iron . . i . . . . \ Iron last ; positive shghtly, then ne- 



L gative. 



C Zinc last ; negative. 

 — plumbago. ♦.< Plumbago last; positive strongly, 



V. then negative. 

 ,j f Zinc last; negative, then positive. 

 S^^^ \ Gold last ; positive. 



rZinc last ; negative slightly, then 

 brass < positive. 



L Brass last; positive. 



Zinc with platina or tin was positive in both cases. 



r Brass last; negative. 

 Brftss with gold < Gold last; positive shghtly, then ne- 



L gative. 



r Brass last ; negative. 

 — — silver . .... J Silver last ; positive slightly, then 



(^ negative. 



r Brass last; negative very slightly, 

 — tin . , < then positive. 



LTin last ; positive. 



Zinc was positive with platina, and negative with iron, in both 

 cases. 



