Two Fluids y and of Two Metals not in Contact. 495 



DIFFERENCE OF THE ELECTROMOTIVE FORCES ON THE CON- 

 TACT OF TWO METALS WITH TWO FLUIDS. 



No. 

 1 



Fliiids of the degrees of concen- 



Zinc. 



Zinc. 



Zinc. 



Zinc. 



tration mentioned. 



Platina. 



Silver. 



Copper. 



Tin. 



Sulphuric acid (s) 



s > w 



s^w 



s < w 



S < it? 





Water (w) 



s ^^w 









2 



Nitric acid (s) 

 Water (w) 



S>'W 



s<w 



°s<: w 



s = w 



3 



Hydrochloric acid (s) 

 Water {iv) 



s -<w 



s <10 



s< w 



s-< w 



4 



Solution of chlorine (c) 

 Water (w) 



o- w 



c-^w 



c <w 



C=:zu 



5 



Solution of chlorine (c) 

 Hydrochloric acid {lo) 



OS 



o- s 



c^ s 



c <s 

 OS 



6 



Caustic potash (a) 

 Water (lo) 



a> 10 



a >' w 



a :::^ w 



a < w 



7 



Ammonia (a) 

 Water (w) 



a > «7 



a'^'W 



a^cw 



a> w 



8 



Carbonate of soda (w) 

 Water {w) 



rKw 



n < w 



n '< w 



?K w 



9 



Sulphuric acid (s) 

 Borax (6) 



s> 6 



s>* 6 



s > 6 



s> & 



10 



Sulphuric acid (s) 

 Iodide of potassium (i) 



s <i 



s >- i 



s >■ i 



s <c i 



11 



H^'drochloric acid (s) 

 Iodide of potassium {%) 



s <i 



s > i 



s >► z 



s < i 



12 



Sulphuric acid (s) 

 Sal-ammoniac (Z) 



s-< Z 



s<: Z 



s > Z 



s <::: Z 



2<; merely weak, already diminishing on the second im- 

 < w stronger than Avith silver, copper, tin ; with tin 



w, m 



1 . With platina s 

 mersion, and then i 

 s < i« increasing. 



2. Results differing with silver, sometimes s = w, sometimes s 

 most cases however decidedly s < tv. 



3. All action feeble ; with copper however pretty strong. 



4. With platina and copper very strong, somewhat weaker with silver. 

 With tin an inclination to c -^w. 



5. 'With platina and copper very strong, with silver weaker, with tin only 

 the first (strong) deflection c < s, immediately succeeded by strong o s. 



6. With silver a>'iu strong, after which, though to a slighter extent, with 

 tin the a<:w. 



7- Strongest effects with silver and copper. 



8. Action feeble, strongest v/'ith. platina and copper. 



9. Action prett}^ strong, weakest with silver. 



10. With platina in two experiments, first s > « vei^y strong, which however 

 rapidly decreased and changed into s <: z quite as powerful. In all the fol- 

 lowing experiments, although the platina was always previously heated, the 

 first effect was s <: i and generally very strong, sometimes moderate at the 

 commencement, and on repeated immersion increasing. — With silver and cop- 

 per action very strong, with tin likewise but opposite. 



1 1 . With non-heated platina, sometimes, but very feeble, s > i, passing into 

 s < i. But with heated platina immediately and very strong s <: i. With sil- 

 ver and copper s > i very strong, with tin s < i moderate. 



12. With copper the s > I strong, still stronger s ^l with tin. With a cir- 

 cuit of tin and copper likewise s>'lm 



