V0: ih. ON SOLUBILITY. 823 
published by Roth.*® He submitted the empirical relationship * ex- 
pressed by 
a—a! 
‘M?/; i 
to exhaustive tests and found it to be valid. 
1899 Euler °° obtained results similar to those recorded by Roth 
in that part of his work which dealt with the solubility of 
ethylic acetate in salt solutions. Thus, the equivalent diminution of 
solubility was found to become greater with dilution of the salt solution ; 
and, if the various salts be arranged according to their values for 
equivalent diminution of solubility, the order of arrangement is the 
same whether the dissolved substance be hydrogen, nitrous oxide, or 
ethylic acetate. The investigation of the absorption of gases by 
1900, #duecus solutions was carried a step further by Braun,™* who 
~~~" studied the solubility of nitrogen and hydrogen in aqueous 
solutions of non-electrolytes and electrolytes at temperatures ranging 
from 5° to 25° C. In the case of electrolytes, the empirical relation- 
ship formulated by Jahn was found to hold. In the case of non- 
electrolytes, if C, represents the molecular concentration of gas in pure 
water and ©, that in the solution of an. indifferent substance, the 
equation C,/C,=1 was found to express the relationship which obtains. 
An extensive investigation of the solubility of various salts of 
calcium, iron, and copper in sucrose solutions of different strength and 
at different temperatures was carried out by Stolle.’ The series of 
results recorded are of great complexity and very difficult to interpret. 
Rothmund ™ brought forward further evidence to disprove the idea 
that salts in solution do not affect the solubility in water of non- 
electrolytes. In this publication the solubility of phenylthiocarbamide 
in water is shown to be diminished considerably by sulphates, car- 
bonates, nitrates, and other salts, the relative order of the salts as 
regards this effect being the same as has been observed when carbon 
dioxide, hydrogen, nitrous oxide, and ethylic acetate were the solutes 
employed. | Work of a somewhat similar nature was published by 
1901 Dawson and McCrae,** who found that the distribution of 
* ammonia between water and chloroform is changed to quite a 
considerable degree by the presence of carbamide and of sucrose. In 
the same year Mellor °° published a research on the solubility of chlorine 
in aqueous solutions of hydrogen chloride. When graphically repre- 
sented, his results exhibited a minimum solubility at about 2 per cent. 
HCl; a fact which the author discussed from the point of view of the 
products formed when chlorine is dissolved in aqueous solutions of 
hydrogen chloride. 
1902 In a paper in which the acid nature of acetylene is dis- 
* cussed, Billitzer 12° showed that sodium sulphate lowers the 
solubility of ethylene and acetylene to about the same extent, but, 
alkalies—NaOH, KOH, and NH,OH—lower the solubility of ethylene 
more than that of acetylene. Lumiére and others °° found the 
* Vide Jahn, Part I. R. 240. 
