[ 401 ] 



XLIV. On a New Method and Department of Chemical 

 Research, By Dr. G. Gore, F.R.S.* 



CONTENTS. page 



Method of Working 401 



Curves of Electromotive Force. . 

 A. By Varying the Strength of the Solution at Both Metals. 



Strength of Solution. 

 Substance. Water. 



Curves of Chlorine, Bromine, and Iodine '001 to '01 grain in 155 grains. 403 



HC1, HBr, and HI. Weak -001 to '01 „ „ 405 



HN0 3 , and H 2 S0 4 „ -001 to '01 „ „ 406 



H,SO 4 at60°C. „ -001 to -01 „ „ 407 



HC1, HBr, and HI. Strong -1 to 1 „ „ 409 



„ HC1 with Cadmium as Positive Metal *1 to 1 „ „ 409 



KCl, KBr, and KI '1 to 1 „ „ 410 



KBr, at60°C '1 to 1 ., „ 4il 



NaCl, NaBr, and Nal «1 to 1 „ „ 412 



KCIO3, KB.O3, and KI0 3 -7 to T7 „ „ 413 



K 2 S0 4 and Na 2 S0 4 -1 to 1 „ „ 414 



KC1 + KI, and KC1+ NaCl '1 to 1 „ „ 415 



„ Isomeric Solutions '01 to "1 ,, „ 416 



B. By Varying the Strength of the Solution at One Metal only. 



Curves of KBr, NaCl, and KCl '1 grain in 465. 417 



C. By Varying the Temperature of the Solution at Both Metals. 



Curve of HC1 from 10° to 100° C '03 grain in 465. 419 



D. By Varying the Temperature of the Solution at One Metal only. 



Curve of Cold Zinc and Hot Platinum from 17° to 100° C. 39 grains in 465. 420 

 Cold Platinum and Hot Zinc from 15° to 100° C. 39 grains in 465. 420 



E. General and Theoretical Considerations. 



Method of Working. 



IN an investigation " On the Change of Potential of a Voltaic 

 Couple by Variation of Strength of its Liquid " (Roy. Soc. 

 Proc. 1888, xliv. p. 296), I showed that by immersing a small 

 pair of unamalgamated zinc and platinum plates in distilled 

 water, then adding to the water successive small and equal 

 quantities of a particular halogen, acid, or salt, until a more 

 or less saturated solution was formed, and measuring by the 

 method of balance with a galvanometer in the circuit, with a 

 suitable thermoelectric pile (see Proc. Birm. Phil. Soc. 

 iv. p. 130 ; also ' The Electrician,' 1884, xii. p. 414), aided 

 when necessary by a zinc-platinum distilled water-cell, or a 

 Clark's standard cell, the degrees of electromotive force pro- 

 duced by each addition of substance, the changes of that 

 force did not vary by a regular gradation. And 1 stated that 



* Communicated by the Author. 



