838 REPORTS ON THE SiaTR OF SCiENCE.—1919. V.c. iti. 
ultimately being reduced below that in pure water.* In the case of 
barium carbonate dissolved in water containing ammonium chloride in 
solution, the solubility of the carbonate was found to increase as the pro- 
portion of added chloride was increased. 
A discussion and criticism of the conception of a ‘ solubility pro- 
duct ’ as enunciated by Nernst} formed the subject of a publication by 
Stieglitz.*** In this communication the author calculates the ‘ solu- 
bility product’ [Cy Cyeia ion] Of silver acetate, propionate, &c., when 
in the presence of excess of the corresponding salts, silver nitrate 
and sodium acetate, &e., from data furnished by the researches of 
Arrhenius. Nernst’s measurements of the solubility of silver acetate 
in solutions containing sodium acetate and silver nitrate (loc. cit.) are 
also recorded. The results obtained indicate that the ‘ solubility pro- 
duct’ has no foundation in fact and must be regarded only as an 
approximate empirical principle which, in the case of the silver salts 
of organic acids, is sufficiently in agreement with observed facts to 
prove of some practical value. Buttle and Hewitt 2? studied the 
influence of silver nitrate, also nitric and hydrochloric acids, upon the 
solubility of silver chloride in aqueous solutions of mercuric nitrate: 
and Baubigny *?* measured the solubility of silver iodide in aqueous 
solutions of ammonia at various temperatures. 
The solubility of the oxalates of the cerium group of elements was 
studied by Hauser and Wirth.**° In dilute solutions of sulphuric and 
oxalic acids differences of solubility were observed and upon this they 
based a method of separating these metals. 
Archibald **? and his co-workers observed that whereas the addition 
of potassium chloride causes a decrease, sodium chloride causes an 
increase in the solubility of potassium platinichloride in water: results 
which are of importance in connection with analytical work. 
1909 In the following year Philip and. Garner *** published a con- 
’ tinuation of their work§ dealing with the influence of salts on the 
solubility of sparingly soluble acids. The conclusions arrived at 
being that sodium salts of weak acids occasion an increased solubility 
of sparingly soluble acids, and the weaker the acid from which the 
sodium salt is derived the greater is this increased solubility. Further, 
if of two sparingly soluble acids the stronger is the less soluble, then, 
under the influence of the addition of any sodium salt, it becomes more 
soluble. The numerical results obtained are in agreement with those 
calculated from Noyes’ formula. Hill and Simmons **! found that the 
laws obeyed by dilute solutions are valid for highly concentrated solu- 
tions of a salt of a weak acid in a strong acid; but the solubility of a salt 
of a strong acid is greatly depressed by some unexplained factor. 
Kohn *°* observed that the solubility of cuprous iodide in solutions 
of potassium bromide increases as the concentration of the latter sub- 
stance is increased. 
1910 The displacement of salts from solution by various pre 
’ cipitants was further investigated by Armstrong and Eyre.* 
eee ee 
* Vide Rothmund, Z. ph. Chem., 38, 401 ; Rothmund and Wilsmore, ibid., 40, 611 
Hoffmann and Langbeck, ibid., 51, 385. 
ft Part I. R. 144. } Zeitschr. physikal. Chem., 31,197. § Part II. R, 226. 
