334 



EEPORT — 1886. 



Solvent Water, 

 (Conductivity/ of Water at 19-8° = ■000O0S48). 



To determine the temperature coefficient of two comparable solutions, j- of an 

 equivalent of dry calcium chloride was dissolved in 250 ccm. of alcohol and water 

 respectively, and the values of the two were determined at two different tempera- 

 tures. 



(1) Alcohol solution : — ' 



~ E. in 250 ccm. solution in cell gave a resistance value of 



236 legal ohms, at 19-4° 



250 



13-6° 



Increase in resistance of 14 for a fall of 5'8° 0. 

 This gives a temperature coefficient — •00102, 

 (2) Water solution : — 

 250 cc. in cell gave value 



R = 14-0 at 18^3' 



R= 15-4 at 14° 



Increase in resistance 1-4 for a fall of 4"3°. 



This gives a temperature coefficient — •0023. 



The results obtained with the two series of solutions have been plotted on 

 curves ; that for the water solution is apparently a straight line, and would tend to 

 show that for solutions of such strength the conductivity is proportional to the 

 amount of salt in solution ; the same does not, however, appear to be true in the 

 case of the alcohol solutions. 



This is a point which of course needs further investigation, and I intend to 

 experiment further on this subject with different solvents and the same salt. 



In conclusion, I have to thank Mr. W. N. Shaw for the kind help and advice he 

 has given me in all this work. 



Professor F. Kouleausch ' Ueher das L&itungsvermijgen einiger Electrolyte 

 in (iusserst \ierdunnter wdsseriger Losung ' (Wied. ' Ann.' xxvi. p. 161). 

 —Abstract by E. F. J. Love. 



This memoir is an extension of previous work, and was undertaken for the 

 purpose of verifying the following laws laid down by Kohlrausch in a former 

 paper : — 



1. If dilute solutions of various salts be prepared, having their strengths pro- 

 portional to the chemical equivalents of the salts, then the specific conductivities 

 of these solutions are all of the same order of magnitude. 



2. In dilute solutions, under a given electromotive force, each of the ions moves 

 through the liquid with a fixed velocity dependent on its own chemical nature, and 

 independent of that of the other ion. This is termed the ' law of independent 

 migration.' 



■3. The influence of change in temperature upon conductivity tends, as dilution 



