352 M. C. Lea—Chloride, Bromide and Lodide of Silver. 
lowed by HCl; by reducing silver citrate by hydrogen and 
treating it with HCl; by treating a soluble silver salt or almost 
any silver solution with potash or soda and almost any reduc- 
ing agent, cane sugar, milk sugar, glucose, dextrine, aldehyde, 
alcohol, etc., and supersaturating with HCl; there is no organic 
easily oxidizable substance that I have tried that has failed to 
give this reaction. Also almost any salt of silver exposed to 
light, treated with HCl and then with hot strong nitric acid 
yields it. Almost any of these classes represents a long range 
of reactions, each susceptible of endless variation. In fact, the 
more the matter is studied, the more extended the range of 
reactions is found to be that give rise to the formation of this 
substance. To show how slight an influence will lead to the 
production of red chloride instead of white: if freshly precipi- 
tated argentic oxide is mixed for a few moments with starch or 
tragacanth paste and is then treated with HCl, the result is, not 
white, but pink silver chloride. Even raw starch flour mixed 
with silver oxide will in a few moments cause it to give a pale 
flesh colored chloride with HCl. Boiled starch or tragacanth 
paste does this more quickly and acts more strongly, even in 
the cold, and still more if heat is applied. 
Although red is probably the most characteristic color of 
this substance, so that I have spoken of it above as red chloride, 
nevertheless this hardly seems a proper name for a substance 
that is often purple, chocolate or black, sometimes brown or 
even ochreous, sometimes lavender or bluish, and is probably 
capable of assuming every color of the spectrum. To call it 
argento-argentic chloride would infer a stoichiometrical composi- 
tion that as already mentioned, seems very uncertain, too much 
so to serve as the basis of the name. Therefore, and as these 
substances have been hitherto seen only in the impure form in 
which they are produced by the continued action of light on 
the normal salts, it might be convenient to call them photosalts, 
photochloride, photobromide, and photoiodide instead of red 
or colored chloride, etc., and thus to avoid the inexactness of 
applying the term red chloride to a substance exhibiting many 
other colors. 
Photochloride by action of Alkaline Hypochlorites. 
Black or purple black chloride is easily obtained by the 
action of an alkaline hypochlorite on finely divided silver such 
as obtained by reduction in the wet way. Commercial sodium 
hypochlorite nay be used to act on it. It is to be poured over 
the silver and after standing a few minutes, is to be replaced 
with fresh. After an hour or two this is again to be replaced 
with a new portion, which is to be allowed to act half an hour 
to insure the total conversion of the silver. The product 
