184 Journ. of the Asiat. Soc. of Bengal.. [July & Aug., 1916, 
presence of AgCl. Carey Lea’s allotropic silver would now he 
classed under the heading of those little known colloidal con- 
plexes which exist in the solid state. 
he two components appear to exercise a mutually protec 
tive influence on each other. This would account for the remark 
able fact that the dark substance is formed in sunlight under a 
dil. solution of HNO, almost as fast as under water or in the 
air. Similarly the disperse phase appears to affect the contin: 
ous one, although to a lesser degree, as may be seen from the 
slower rate of solution of the AgCl in ammonia in the case di 
the darkened product. 
From this point of view the necessity of assuming the 
existence of a hypothetical subchloride is dispensed with. The — 
properties of this body have always been extremely vague and 
elusive, and adaptable just as the exigencies of the facts de 
manded. The other compounds on whose analogy its formuls 
was ascribed have been proved to be illusory, such as Ag,0 am 
the monochlorides of Ca, Sr, and Ba. 
There is no direct evidence of the existence of Ag,Cl what 
ever, and Luther’s work on the electrochemical potential of 
photochemically reduced AgCl which was supposed to hare 
demonstrated the existence of Ag,Cl, is now recognized to have 
the first place, the assumption of the existence of at 
oxychloride is not warranted by the experimental evidence * 
much as the reactions observed can all be explained on t¥ 
supposition that Ag.O is present. This would account for the 
presence of a slight excess of silver in the ammoniacal solalt 
obtained by the action of conc. NH ,HO on the photoehloriéé 
and it also explains the production of alkali with KCl in 
dance with the reaction. 
Ag,0 +2 KCl +H,O=AgCl + 2 KHO. 
In a paper recent y publi i d Bydmant 
published by Kohlschiitter und 2Y™ 
(Annalen Band 398) it has been shown that oxidation of silvet 
a state of such fine division. In : red ip tht 
d . photochloride prep ee 
Meee ‘shy which was also found to contain oxygen, 4 th io 
Smaier amounts, it is to be observed that colloidal sil 
never yet been prepared containing 100% of Ag, and that 
