380 H. Wurtz’ Contributions to Analytical Chemistry. 
its crystal-water, was boiled with acid of 1°48 sp. gr., and dis- 
solved with difficulty, giving off brown gas. The clear colorless 
solution was evaporated slowly, raising the heat towards the 
last until al! free acid was expelled. The crystalline residue dis- 
solved completely in water and the solution contained both eblo- 
rine and nitric’acid. 
was found. 
Crystals of CuCl+2HO were heated cautiously until converted 
into the brown anhydrous chlorid, which then slowly dissolved 
when heated with nitric acid of sp. gr. 1:48, with evolution of 
brown gas, to a blue liquid. This liquid, evaporated to dsr 
at a very gentle heat left a blue crystalline residue, which sth 
contained a trace of chlorine and was altogether identical with 
the one above described. 
17. Chromium.—The chlorid of this metal yielded very pein 
After the first evaporation with nitric acid no chlorine could be 
detected. se le a 
18. Uranium.—tThe residue after the first evaporation of t . 
terchlorid with nitric acid crystallized beautifully in lemon-ye* 
low prisms of the well-known compound of nitric and uranic 
acids. They contained no trace of chlorine. 4 1] 
19. Subchlorid of Mercury.— According to A. Vogel, | calome! 
dissolves in hot nitric acid with evolution of nitric oxyd as Pr? 
tochlorid and nitrate of the protoxyd, 
8lg?C1+4NO°=3HgCl+3(Hg0, NO*)+NO. 
h the heat 
ach cancion, and 
ich requires coh 
+ Gm. Handbuch, iii, 417. F olor im- 
{ Gladstone (Liebig and Kopp’s Jahresb. 1855, p. 415,) describes vag ie it 
d to copper solutions by excess of HCl as yellowish green. To my 0" 
ap as above. f the next 
| The application of the indigo test to Cu solutions as also to those OF | paper 
two metals, Cr and U, requires in precautions to be described in a special pap 
on the subject before alluded to, which is in course of preparation. 
. j Ga. iii, 512. 
