- = ae r 
_H. Wurtz Contributions to Analytical henistry. 85 
ammonia. Under these circumstances the decomposition =. 
ceeded rapidly, and the mass soon pr - 
tranquil fusion, with much white sediment, ae Zyarres no 
more gas. eat was finally raised to redness me min- 
utes, On olin , hot water was added, the pare diluted and. 
thrown upon a fi ter, together with the washings of the platinum 
foil and crucible cover; these, together with the crucible itself, 
being put aside for further use, it being found that a small quan- 
f the magnesia remained adhering to them. The mass 
remaining on the filter was washed with boiling water, and the 
solution. After a long time a very minute precipitate 
but at the same time the liquid became loaded witht itters of 
silica, proceeding from action of the solution of alkaline carbo- 
nates on the glass, and a slight error was thus introduced into 
the result. The filter with the magnesia was burned in the same 
crucible, the combustion being found surprisingly easy, and the 
magnesia weighed 0°44 gram. The precipitate obtained by = 
carbonic acid (with intermixed silica, as well as some lime, a 
wards found in it, derived also from the glass) weighed ‘half 2 
uligram , making the whole product weigh 0°4405 gram, against 
04392 taken. On dissolving the product in chlorohydric acid, 
the silica remained behind as a very perceptible residue, and the 
solution contained also a distinct trace of platinum, though the 
loss of the crucible during the operation was not more than one 
fifth of a milligram. ne poe however, it would seem 
to use a silver crucible. 7 
In the above riment no attempt was made to determine 
the alkalies in the filtrate, but the esti with the magnesia being 
une successful, for a first attempt, another experiment, 
with this in view, was proceeded to. 0°3627 gram of magnesia, 
0°6092 of chlorid of potassium, and 0°816 of chlorid of sodium 
were taken. The mode of proceeding was the same as before, 
except that the application of the carbonate of ammonia was 
ca continued, and after the decomposition of the nitrates, 
mass was dissolved in hot water, a feeble current of carbonic 
ae passed through the liquid whi le still in the crucible, and the 
latter heated on the Cnt ge Pp: ‘om ee a The 
filtrate was supersaturat with chlorohydric acid, evaporated to 
, ‘ignited residue weighed, ie chlorine ReGrtned as 
AgCl, and the : proportions of the two chlorids calculated in the 
usual manner in indirect analysis. The results were 03631 of 
magnesia, 0607 of chlorid of potassium and 0°8111 of chlaia. of . 
sodium. 
