412 



Dr. Gr. Gore on a 'New Method and 



Volts. 

 1-21 



1-20 



1-19 



1-18 



1-17 



ri6 



1-15 

 1-14 

 1-13 

 1-12 



Fig. 10. 



Curve of KBr at 60° C. 



^H 





wj& 



^^^mBiw 



■ 





"'- 



m i 



II 





< f ."<>v,''" ■ - 



.'»'-• 1 



M 



B 





1 











O >Q O lO 



Grains. T" 1 t 1 ^ ?>m ^ > "? t 1 "P *P *P *P 



On comparing the two curves obtained at the two tempera- 

 tures we find considerable differences, viz. : — 1st, A great 

 unlikeness of general form. 2nd. A general and large 

 diminution of electromotive force at the higher temperature. 

 And 3rd. A much smaller increase of that force on the 

 addition of the first portion of the substance. The differences 

 would probably have been less conspicuous if the solutions 

 in each case had been much weaker. These results support 

 the conclusion that potassium bromide behaves to a certain 

 extent like a different substance at each different temperature. 



9. Curves of NaCI, NaBr, and Nal. 



The chloride contained a trace of sulphate, and the bromide 

 and iodide were very faintly alkaline. The solutions were 

 of the same range of degrees of strength as the corresponding 

 salts of potassium ; and the curves are drawn upon the same 

 scale of magnitude. 



These curves show: — 1st. A general increase of electromotive 

 force by increase of dissolved substance. 2nd. A great 

 difference of form, and strongly characteristic curve in each 

 case. And 3rd. The substitution of sodium for potassium in 

 each salt considerably reduced the degree of. electromotive' 

 force produced by the first addition of the substance, and the 

 amount of this reduction varied inversely as the molecular 

 weights of the salts. The curves are widely different in form 

 from those of the corresponding salts of potassium, and this 

 is no doubt entirely due to the difference of metallic base ; in 

 each group, however, the curve of the chloride intersects that 

 of the bromide. 



