ON ELECTROLYSIS IN ITS PHYSICAL AND CHEMICAL BEAHINGS. 337 



very dilute solution of HCl was fouud to slowly diminish, owing to tlie withdrawal 

 of "the acid from the solution. That this is due to the electrodes was shown by an 

 increase in the resistance on sinking them in the fluid, the higher conductivity being 

 restored by stirring. The phenomenon is 'not exhibited by solutions of neutral salts. 



3. The specific molecular conductiyity of a strong base or acid is diminished by 

 gradual neutralisation, reaches a strongly defined minimum when neutralisation is 

 complete, and thence increases. Phosphoric acid seemed to show several such points 

 of discontiniuty ; acetic acid gives a curve of graduaUy changing curvature, the 

 neutralisation point being apparently somewhat indefinite. 



4. The behaviour of the tree-formed deposits on cathode, out of very weak solu- 

 tions. The threads are less than -001 centim. thick ; they repel one another, while the 

 current is passing, like a head of hair on an electrical machine, and with high E.M.F.'s 

 they are continually in motion. 



Addenda. By Oliver Lodge. 



To this brief abstract of an important memoir it may he convenient to append a 

 few of the numerical results, since they are interesting in themselves and important 

 to Arrhenius' theory of chemistry (see below). Moreover, these determinations of 

 Kohlrausch are probably a long way the most accurate at present made. 



First comes a table of molecular conductivities ( — j multiplied by lO^ for con- 

 venience. The top line of the table gives the strength of the solutions, in gramme 

 equivalents of the substance per litre, For example, the first entry (1216) means 

 that a solution of potassic chloride containing -000746 gramme of the salt in each 

 litre has a specific conductivity 1216 x '000746 x 10"^ times that of mercury. A 

 line is drawn across the table to divide the curiously behaving acid and other 

 bodies from the more neutral substances. 



Abridged Table of Molecular Conductivities for different substances at various 

 concentrations, according to Kohlrausclis latest determinations. Tabulated 



Numbers, 10' — , cohere m is gramme^equivalents per litre. 



1886. 



