Vol. XI, Nos. 7 & 8.] Action of Light on Silver Chloride, 183 
[V.8.] 
of the matter lies in the fact that it is impossible to distinguish 
between small amounts of the oxygen compound of silver 
cold dil. HNO;. By continually substituting fresh amounts of 
hot dil. HNO, small traces of Ag could be dissolved out at 
infinitum. Again by the action of some solvent for AgCl such as 
NH,HO, KCl, KON the residue obtained in every case was 
hothing but metallic Ag. ‘The darkened product was found to 
tesist Some solvents better than others, thus KCl only dissolved 
out small quantities at a time of AgCl, but there was at the 
‘ame time no point at which the action ceased. 
n one experiment it was attempted to act upon AgCl 
crystallizing out from cone NH,HO in the presence of sunlight. 
4 remarkable dark crystalline substance was obtained, denser 
than AgCl and containing about 24% of reduced Ag. Thi 
substance was extraordinarily stable. No Ag could be dissolved 
out even by cold conc. HNO,. NH,HO acted upon it very 
slowly indeed. Prolonged treatment with boiling acqua regia 
*onverted into the normal chloride. 
ted and 
ductg m 
/;. The best way of showing t -Bacscieh : 
80 Partially reduced by tis action of heat, strike it up with 
. nd Ww h “ 
