M. ©. Lea—Chloride, Bromide and Iodide of Silver. 35% 
If we suppose that all the silver was combined with chlorine, 
the constitution of the substance would be: 
aN Ol oe ER 92°49 
HNC 0) Ve eye Cee a 7:51 
100°00 
but this was probably not the case, there was almost certainly 
free silver present and consequently a less proportion of sub- 
chloride. Another specimen, treated repeatedly with hot acid 
until every trace of free silver was removed was found to con- 
tain 1:52 per cent of subchloride, color purple. Another 
similarly treated contained 7:3 per cent subchloride. 
Action of Nitric Acid on Silver Subchloride. 
When freshly precipitated and still moist subchloride of 
silver is treated with nitric acid, a sharp effervescence accom- 
panied with a disengagement of red fumes, sets in; presently 
the strong red co.oration of the photochloride appears and the 
action ceases. This production of the red and not the white 
chloride in the decomposition of Ag,Cl is precisely what might 
have been expected, for when AgCl is formed in the presence 
Ag,Cl more or less combination always takes place. 
The action is interesting in this respect: the AgCl first formed 
is at the moment of formation in presence of all the yet undecom- 
posed portion of Ag,Cl, and whatever. part it combines with is 
removed from the action of the acid. It would therefore seem 
probable that this method would be one of those that yielded 
a product having the largest proportion of Ag,Cl, but analysis 
showed that different specimens were extremely variable—ot 
those analyzed, one contained 8°62 per cent of Ag,Cl, another 
6°56, and a third 1:96. All that analysis can do with such 
substances is to fix the limits within which they vary. The 
quantity of subchloride left after treatment with nitric acid de- 
pends partly on the strength of the acid and the time for which 
it is allowed to act, but also to some extent on variations in the 
resistance of the substance itself. These specimens were of 
shades between rose and purple. 
The color of any particular specimen is always lightened in 
shade by abstracting Ag,Cl from it by continued boiling with 
nitric acid. But as between different specimens, especially 
when formed by different reactions, it by no means follows that 
the darkest in color contains the most subchloride. 
Argentous chloride when treated with sodium hypochlorite 
yields a purple form of photochloride. A specimen so treated 
contained 2°57 per cent of Ag,Cl. 
