820 REPORTS ON THE STATE OF SCIENCE.—1912. V2.4, « 
Very interesting results were obtained by studying the effect pro- 
duced by pressure on the solubility of gases in liquids when in the 
presence of some other substance. Drucker and Moles **? worked with 
hydrogen and nitrogen, and found that when these gases are dissolved 
in mixtures of water and iso-hutyric acid, Henry’s rule is obeyed even 
at the critical solution point of the two liquids. Findlay and Creigh- 
ton *°* experimented with fine suspensions of silicic acid and ferric 
hydroxide in water, and found the solubility of gases in these solvents 
was affected by pressure in those cases in which the presence of the 
colloid altered the solubility of the gas. 
Sieverts and Krumbhaar **8 observed that when gases dissolve in 
metals—for example, sulphur dioxide dissolving in copper or oxygen 
in alloys of gold and silver—the solubility is proportional to the square 
1911, Toot of the pressure. In a subsequent publication 4° this was 
“~*~ also found to be true of solutions of hydrogen in copper, iron, 
and nickel, except at pressures below 100 mm., when no such relation- 
ship was observed. 
V. C.—Influence of other Substances. 
(1) Non-electrolytes influenced by Non-electrolytes. 
1896 Tolloczko ® made numerous experiments with the object of 
’ studying the solubility of ethylic ether in water as affected by 
the addition of various organic substances. The results he obtained 
seemed to be in support of Nernst’s theorem.* Results which were 
1997, Bot in harmony with the requirements of this theorem were 
““"* recorded soon afterwards by Schiff,?”7 who observed that certain 
organic substances—phloretin for example—are much more soluble 
in ether which is saturated with water than in either water or 
ether alone.t In the same year Benedict** published observations 
of a similar phenomenon with camphor and with naphthalene, and, 
although Talmadge *’ was unable to confirm completely these results 
with naphthalene, his work showed that the vapour pressure of a 
solute does vary with different solvents. In the case of camphor 
the values with ether and acetone are more than double the real vapour 
_ pressure; with methylic alcohol the calculated vapour pressures are 
a little above the normal and with ethylic alcohol only about one-half 
those found experimentally. 
1900 Braun ™* determined the absorption coefficient for nitrogen and 
‘ for hydrogen in aqueous solutions of carbamide and propionic acid 
at various temperatures between 5° and 25° C. He found that the 
solubility relationship could be expressed by the equation C,/C,=1, in 
which C, =molecular concentration of the gas in pure water, and C,= 
molecular concentration in the solution of one of the so-called indifferent 
substances at the same temperature and partial pressure. 
In so far as the solubility of p-nitrophenol in benzene, m-xylene, 
and chloroform is increased by the addition of small quantities of 
1901 water, the observations made by Lotmar ** were confirmed by 
‘ Meyer.1> It was, moreover, further established that the addi- 
* Vide Part I., R. 144. 
+ This author’s original notice of these facts is to be found in Ann. d, Chem. [1885], 
229, 371. 
