V.c. iii. ON SOLUBILITY. 839 
The solubility of ammonium, sodium, and potassium chlorides in dilute 
aqueous solutions of hydrogen chloride; potassium chloride in solutions 
of potassium nitrate; potassium nitrate in solutions of potassium 
chloride, and sodium chloride in solutions of sodium nitrate were all 
measured at 0° C. and 25° C., and the results contrasted with similar 
data relating to these salts dissolved in aqueous solutions of various 
aleohols. This work confirmed the conclusions drawn from their pre- 
vious research * and showed even closer agreement in the behaviour of 
these different precipitants than was formerly pictured. 
Hill *8° measured the solubility of thallous chloride in acetic acid 
solutions of various strengths and of tetramethylammonium iodide in 
solutions of caustic potash, and the results were viewed as confirming 
the conclusions drawn by Cameron} and by Hill and Simmons? that the 
“solubility product’ is not a constant quantity. On the other hand, 
Washburn,**> making use of his simplified application of thermo- 
dynamics to chemistry, claimed to have disproved the contention of 
Stieglitz§ that the theoretical basis for the ‘ solubility product’ is non- 
existent in the case of strong electrolytes, because they do not obey the 
law of mass action. 
Only brief mention can be made of the many papers bearing upon 
the subject of solubility variations which were published during 1910. 
Van Dorp *** studied the system sulphuric acid—ammonium sulphate— 
water, and the system sulphuric acid—lithium sulphate—water, at 
30° C. Beck and Steqmiiller *** examined the influence of hydrochloric 
acid upon the solubility in water of lead sulphate and chromate. 
It was found by Parsons and Perkins **7 that barium nitrate and 
baryta mutually render each other more soluble, and the same was 
found to be true in the case of strontium nitrate and hydrate. Similarly 
Herz **? found the solubility of baryta was increased by the presence 
of alkali chlorides, but the solubility of the sulphates of potassium, 
sodium, and ammonium were found by D’Ans and Schreiner*®* to be 
lowered by the presence in solution of the corresponding alkali. 
The equilibrium relationship for the reciprocal salt pairs KCl+ 
NaNO, < NaCl+KNO, was determined by Uyeda.*®® The increased 
solubility of silver sulphate when dissolved in presence of alkali sul- 
phates formed the subject of an investigation by Barre,*7* and 
Rindell *** studied the changes of solubility of calcium carbonate in 
water which are brought about by adding small quantities of ammonium 
salts to the solvent. 
Herz **° observed that the solubility of succinic acid is lowered con- 
siderably by the presence in solution of alkali salts; the lowering effect 
being reciprocal. The same author **' found that benzoic and oxalic 
acids mutually render each other more soluble when dissolved together 
in water. 
1911 A research was instituted by Noyes and others to test the 
“validity of the so-called ‘ laws’ of solubility influence, (i.) that 
the ‘ solubility product ’ of the ions is a constant, (ii.) that the concen- 
* Part IT. R. 305. + Part IT. R. 99. 
{ Part IT. R. 361. § foc. cit, 1908, 
