454 REPORTS ON THE STATE OP SCIENCE. 



application by Nernst of the law of ' Mass action ' was further 

 discussed by Le Blanc and Noyes, 165 who cited several examples of 

 apparent anomalous behaviour; as, for example, mercuric chloride and 

 hydrogen chloride, sodium chloride and potassium chloride, and 

 potassium nitrate and lead nitrate, while sodium nitrate behaves in a 

 normal manner. In these and in other cases of increased solubility, 

 from freezing-point measurements of combination between the two 

 instead of the anticipated decrease, they were able to obtain evidence 

 added electrolytes. In further support of Nernst's hypothesis, the 

 conclusion was arrived at that the solubility of a substance in water 

 is not much influenced by the presence in solution in the water 

 of another substance which does not of itself play the part of a 

 solvent. 



The complex case of mutual salt influence when double salt forma- 

 tion takes place — potassium sulphate with copper sulphate — was 

 iQQi examined by Trevor. 177 Compared with their solubility in pure 

 water, he found the solubility of the more soluble salt was 

 increased, and that of the less soluble salt diminished. This is in 

 agreement with Nernst's hypothesis, as was pointed out by Noyes. 16 * 



A paper entitled 'Neutral Solution,' by Nicol, 1&i continued the 

 discussion of phenomena due to the mutual influence of two salts on 

 each other's solubility in water*; more particularly of chlorides and 

 nitrates of sodium and potassium in sucb combinations that the salt 

 pair contained a constituent in common. 



The general conclusion come to was that the presence of one salt 

 diminishes the solubility of the other, except in the case of the nitrates, 

 where an increased solubility was found. 



The research of Bodldnder 176a on the influence exerted by one salt 

 on the solubility of another — potassium chloride precipitated by potassium 

 nitrate — furnished results which were not in agreement with the views 

 held by Nernst. Bodlander found, for instance, in the above case that 

 the same relationship existed between water and dissolved salt- — 

 potassium chloride — as was found when alcohol was the added sub- 

 stance and not potassium nitrate. 



Roozeboom 183 determined the solubility of mixed crystals of the 

 isomorphous salts, potassium chlorate and thallium chlorate, and ex- 

 pressed views as to the limitations of Nernst's law of the relative lower- 

 ing of solubility. 



Setschenoff 1Si examined the data published in connection with 

 Bodlander's work, and found that, provided the concentration of the 

 solution is not great, the solubility of one salt in the solution of another 

 indifferent salt obeyed the law he had observed to hold for the 

 absorption of carbon dioxide in salt solutions. 



Tbis line of work was continued by Blarez, 169 who employed 

 potassium hydrogen tartrate and studied the influence of varying 

 quantities of potassium chloride on its solubility. 



Besides the solubility of this tartrate being a function of the tem- 



* Trevor, Phil. Man. (5) 32. 75, pointed out that the problem discussed in this 

 paper had been solved theoretically and confirmed experimentally by Nernst, Noyes, 

 and himself. 



