Rahtite, Marcylite and Moronolite. 213 
also be driven off,) I proceeded as follows. The hygroscopic 
water was first determined by heating the substance at 100° c, 
until the weight became constant, then by strong ignition in a 
platinum crucible over a gas-blast (“ gas-geblise”), al! the chem- 
ically combined water and a great part of the sulphuric acid were 
driven off, and the loss of weight was noted after the operation, 
The residue was treated with hydrochloric acid, in one case, in 
the other it was melted with carbonate of soda, and the remain- 
ing sulphuric acid was precipitated from the solution with chlorid 
of barium, and determined in the usual manner. In another por- 
hon, the sulphuric acid, the whole amount was found. Know- 
ing now the amount of water and sulphuric acid together, and 
of the latter alone, the water is determined by the difference. 
The results of the analyses are as follows: 
A previous Without the hyg-. 
No. land2, No.3 and 4. analysis. Average. HO and the Insol., 
ee i 29-29 29-08 ~_ 29°19 34-17 
e failed 40°05 46°89 
Al203 “p t 41°19 40°32 } ae i 
Cad 94 am ais 94 1:10 
NaO ) . 
KO | 288 3°26 2-79 3-26 3°81 
HO 10-83 11-26 13°18 
HO hygrosep, 1:46 ' weiss 1-62 | 153 ary! 
Tusol. 11°35 11°05 11:10 1117 ile 
98°11 99-98 
_ This result agrees pretty well with the two analyses of “ Gelb- 
fisenerz” (from Bohemia and Norway) by Rammelsberg and 
Scheerer, given in Rammelsberg’s Mineralchemie. I annex them 
for comparison. , 
Ox.ratio Rammels- 
By Rammelsberg. Oxygen. By Scheerer. Oxygen. ofabove. berg’s ratio, 
om 3211 19 32:48 19°47 20°50 15 
* 4673 1402 . 4963 14°89 Pe | : 
) 788 Cee Cares 
NaO i ee ee st 98 
Cad Oee a I. pena 
HO 13:56 1205 1311 11°64 11-71 9 
100°92 100°39 
The formula of the mineral therefore would be this, E544 5) 
+94q.; the only peculiarity being that while the above have each 
but one of the alkalies, they are both present in the Moronolite. 
* As the amount of alkali found was in all cases too small, I have taken the larg- 
est one here, instead of the average, as most correct. 
