and the Products of its Transmutation. 133 
A. SUBSTITUTION OF POTASH FOR SODA. 
1.—Pseudomorphous Mica after Wernerite. 
At Arendal large Wernerite crystals occur in quartz. Their 
‘surface is entirely covered with scales of mica, and the sub- 
stance of the crystals consists, moreover, entirely of the same 
‘mica, intermixed with quartz, small crystals of pinguite, and 
sometimes a soft green substance, which appears to be inter- 
mediate between Wernerite.and mica. The mica is greenish 
white and transparent. Its density is 2833. Analysis gave: 
I. II. Ii. 
Silica, . 4 . 44-49 Re 44°49 
Alumina, ‘ : } 99-39 25°35 24:91 
Peroxide of iron, 4°84 4:84 
Lime, . : ‘ pricy ae 2°37 2:14 
Magnesia, . ‘ sey 6 ae 0:50 0°36 
‘Potash, . 4 : Yo cthe 6°71 6-71 
Soda, 5 ; om FAt Teil 
Water, ; ‘ i) B44 oad 3°44 
Carbonate of Lime, gy pide Wao) dy UA Livi 
The quantities of oxygen are,— 
Silica, . : : ; 25:09 + 
Alumina, . . 10°84 a 
Peroxide of iron, . %, 246 } elk ty 
Lime, . : ; ~;, 0.61 
Magnesia, . . O14 : 
Rei Shien oy raga rg 2 P88 
Soda, 3 y Fo OSB 
Water, : ; . 8:06 
The analysis of this pseudomorphous mica shews that it 
differs from other potash mica, especially in the large pro- 
portion of bases RO to those R, O,; and in the large pro- 
portion of silica to the two classes of bases. The formula 
expressing its composition is :— 
KO, SiO, +2 Al, 0, SiO, 
And the oxygen ratio for KO: Al, O, : SiO, =1:6: 9. 
_ ~ Comparing the composition of this mineral with that of 
__ scapolite, it will be seen that the proportion between the 
Silica and the weaker bases is much the same; while the 
___- proportion between it and the mono-atomic bases is widely 
different. Their total quantity of oxygen is little more than 
