124 DR. B. D. STEELE, DE. D. McINTOSH AND DR. E. H. ARCHIBALD 



cooled platinum spoon. The mixture was then stirred until the conductivity remained 

 constant, after which the volume of the solution was observed. A further weighed 

 quantity of the substance was then introduced and dissolved, and the conductivity 

 again measured. The same series of operations was frequently repeated until a 

 sufficient number of measurements had been made. 



Other measurements were made in the apparatus shown in fig. 3. This consisted 

 of a graduated test-tube A, provided with fixed electrodes, and with a delivery tube 



B attached. 



A saturated solution of the substance was made in the apparatus shown in fig. 1, a 

 portion removed for analysis, and a sufficient amount put into the conductivity vessel, 

 where its conductivity was measured and the volume noted. More of the solvent 

 was then added, and the liquids were well mixed by blowing air through the delivery 

 tube B. The volume was again read and the conductivity measured. 



This succession of operations was repeated until the vessel became full of liquid, 

 after which a measured volume of the solution was removed, and the operations were 

 continued until a sufficient number of measurements had been obtained. 



In all the measurements the electrodes were sufficiently immersed to give the 

 maximum conductivity of the apparatus. 



Our results are given in the following tables, which also contain the temperature 

 coefficient of conductivity for those solutions which are marked with an asterisk. 



The dilutions, which are given under V, represent the number of litres of solution 

 which contain 1 gram-molecule of solute, and the molecular conductivities in reciprocal 

 ohmsx 10~ 3 are given under p. The numbers are thus expressed in the same units as 

 the molecular conductivity of aqueous solutions as given by KOHLRAUSCH and 

 HOLBORN (' Leitvermb'gen der Elektrolyte '). 



TABLE I. Solvent : Hydrochloric Acid. 



