1902 Donnan] ABSTRACT 53 



di-methyl-pyrone moves into the cathode compartment. The 

 first apparatus was a beaker into which dipped tubes closed 

 underneath with parchment and containing the electrodes and 

 hydrochloric acid. The second was a vertical U-tube, the 

 upper halves of whose arms were attached by ground glass 

 joints so that they could be separated by sliding horizontally ; 

 the lower half contained the di-methyl-pyrone. 



igo2. F. G. Donnan, H. B. Bassett and C. J. J. Fox. 



The Color Changes exhibited by the Chlorides of Cobalt and some other 

 Metals, from the standpoint of the Theory of Electroatrinity. Jour. Chem. Soc, 

 Si, 939- 



Two electrode chambers are connected by a horizontal tube 

 closed at each end by a plug of plaster of Paris. When the 

 electrode compartments were filled with strong solution of cal- 

 cium chloride and blue cobalt chloride, and the horizontal tube 

 with calcium chloride solution, the blue color traveled down the 

 tube toward the anode. When the end vessels contained red 

 cobalt chloride and the tube potassium chloride, the red color 

 moved toward the cathode. Cataphoresis was not measurable. 

 Further experiments were performed in a U-tube, the lower 

 half containing the heavy solution, and both arms the other 

 (electrode) solution. 



L,ower Colored Layer. Upper Colorless Layer, 



(i) C0CI2 (blue) in concentrated HCl concentrated HCl 



(2) " " " " MgCl, " MgCl, 



(3) " " " " CaCl, " CaCl, 



(4) fairly dilute CoClj (red) KCl 



(5) C0CI2 (red) + concentrated CaClj and ZnCl, concentrated CaCl.^ + ZnCl^ 



(6) Fehling's solution alkaline tartrate solution 



(7) ammoniacal copper sulphate NH4OH + NH^SO^ 



(8) C0CI2 (blue) in alcohol CaCI, or HCl in alcohol 

 (8«) C0CI2 (red) in alcohol at —79° CaClj or HCl in alcohol 



(9) C0CI2 (red) + HgClj in alcohol Hg.Clj 

 (to) " " " " " " HCl 



(11) FeClj in concentrated HCl (concentrated HCl) .? 



(12) CuCU " 



In (i), (2), (3), (6), (8), the blue color moved toward the 

 anode ; in (4), (5), (7), (9) and (8a) the red color moved towards 

 the cathode ; in (10) the blue meniscus on the anode side moved 

 off toward the anode leaving a colorless layer above the red 

 solution, at the cathode side the blue color at the meniscus ex- 



