376 Hf. Wurtz Contributions to Analytical Chemistry. 
easily detected, but on moistening the residue with the same 
nitric acid and reévaporating, no trace of chlorine was found in 
the second residue. With crystallized chlorid of magnesiu 
the same results were obtained. Two evaporations with excess 
of acid seem to be sufficient under ordinary circumstances to 
complete the decomposition, and in favorable conditions it may 
be effected by one. Thus pure crystals of the chlorid MgCl+ 
6HO, dried by pressure between folds of paper, were heated 
‘ pa ran is ; : 
r : 
at 60° C., quickly dissolving to a clear yellow solution. The 
evolution of gas however was not copious even at 100° C.; but 
As in the case of chlorid of sodium, an attempt was made to col- 
lect the gas over hot water, which failed for the same reason as 
in that case. On cooling to the temperature of the air, no change 
took place in the liquid, and none on the addition of alcohol m 
large quantity. 
5. Calciwm.—Experiments were made with a concentrated 
solution of the pure chlorid, with the crystals, and with the ar 
hydrous salt. In each case, one evaporation expelled every trace 
of chlorine. se 
6. Strontium.—Parallel experiments, as in the case of calcium, 
were made with this chlorid in solution, crystallized and dry, 
and with similar results. habs 
7. Barium—With the chlorid in solution, crystallized, an 
dry, results similar to those under (5) and (6 be 
Chlorid of barium in the solid form appeared however to } 
group, requiring generally one or more repetitions of wre 
alth 
fact 
adiness. This 
Se 
elief founded upon the fact that when a strong soinaon dilute, 
chliorid is added to nitric acid, unless the latter be very ¢ chlo- 
a oy aoe appears, which has been supposed ge: 5 
: oa 
a salt which is to be examined (for sulphuric acid) npr 
or nitric acid has been added, it must still be remarked tha 
BD Aeelht t re lytischen Chemie, i, 485. 
