20 
CONTRIBUTIONS TO CHEMISTRY AND MINERALOGY. [bull. 167. 
Fractional water. 
At 100° 
0.58 
1.16 
3.64 
1.57 
1.90 
0.11 
none 
At 180° 
At 260° 
At 300° 
Low redness 
Full redness 
Blast 
8.96 
The fractional water determinations were made by heating in an air 
bath to constant weight at each temperature up to 300° and finally 
over the direct flame. The first fraction, at 100°, is evidently hygro- 
scopic or extraneous water, which can be disregarded. The remainder 
of the water, 8.38 per cent, belongs to the species. The significance of 
the analytical figures will be considered later. 
Upon boiling the powdered analcite with sodium carbonate solution, 
250 grams to the liter as in all the preceding experiments, 0.73 percent 
of silica was extracted. After ignition the mineral in two determina- 
tions yielded 1.46 and 1.38 per cent respectively. The splitting off of 
silica is therefore very slight; and one of the formula proposed by 
Doelter, 1 Na 3 Al 2 Si 2 8 + 2H 2 SiG 3 , may be set aside as improbable. Meta- 
silicic acid or an acid metasilicate can hardly be present in analcite, 
although the possibility of a neutral metasilicate, as indicated by the 
empirical formula, is not excluded. By Doelter's formula one-half of 
the silica ought to be removable. 
Upon heating analcite with dry ammonium chloride results of a 
remarkable character were obtained. Sodium chloride was formed 
which could be leached out by water and measured, while ammonia 
free from chlorine was retained by the residue to a notable and sur- 
prisingly stable degree. The experiments in detail were as follows: 
A. Analcite, mixed with four times its weight of ammonium chloride was heated 
for four hours to 350°. There was a gain in weight of 2.18 per cent, and 6.10 i>er 
cent of soda, or one-half of the total amount, was converted into NaCl, which was 
leached out by water, examined as to its purity, and weighed. In the residue 1.20 
per cent of silica was. extractable by sodium carbonate, showing that no more 
splitting off had occurred than was previously observed. The gain in weight, as 
will be seen from subsequent experiments, is due to the fact that all of the NfLCl 
had not been driven off; or else that more water was retained. 
B. Analcite was ground up with four times its weight of NH 4 C1, heated for 
several hours, reground with another fourfold portion of chloride, and heated to 
350° for twenty-one hours. Gain in weight, 0.08 per cent; 5.57 per cent of soda was 
extracted as chloride. 
C. Analcite heated to 350° for eight hours, with four times its weight of NHjCl. 
Loss of weight, 0. 10 per cent. 
1 Xeues Jahrb. fur Min., 1890, Vol. I, p. 133. 
