168 GEOLOGICAL RECONNOISSANCE 
For No. 21. 
Peroxide of manganese.+..-.-- 57.92 contains O 21.27 
Protoxide of manganese ----.-- 89.88 7 8.97 
Baryta oe eee Re ea Rw eee a ee 0.29 “ 0.03 9.93 
Dime: hese hited tei hls 1.27 “ 0.36 . 
Water eee eoe ee a a ee ee ee ee 0.64 66 0.57 
Rammelsberg does not include water under the bases of the constitution 
RO; but seeing no objection to its being considered isomorphous with CaO 
and BaO, and gaining the advantage of a simple formula, I have classed 
it with these bases. From the above oxygen-ratio, we obtain for the two 
minerals the general expression: 
RO. MnO?-|-x MnO? 
in which x MnO? stands for the amount of peroxide of manganese which 
must -be considered as mechanically intermixed with the compound 
RO.MnO?*. For the potassa-psilomalane from Ilmenau, Rammelsberg 
deduced the formula 2 RO. MnO®-x Mn02, 
e 
For No. 20 we finally obtain the expression: 
(MnO. BaO. HO). MnO*-|-6.37 per cent. of MnO? 
mechanically intermixed. 
For No. 21 
(MnO. BaO. CaO. HO).MnO®-|-3.84 per cent. of MnO? 
mechanically intermixed. 
Uniting in analysis of No. 22, the free oxygen with a portion of the pro- 
toxide of manganese to the formation of peroxide, we have: 
Peroxide of manganese--.-..+. 62.41 contains O 22.92 
Protoxide of mangauese--..-.- 19.08 te “ 4,29 
Barytas sees cece reece eeneee 2.75 “ “© 0.52 4.84 
Oxide of cobalt .-++-+-++++..ee- 0.15 ef * 0.03 
Wratereaiadag ees eaweaeacngan 15.61 “ 13.97 
100.00 
The formula 
(MnO. CoO. BaO). 2 MnO?-|-3 HO-'-x MnO? 
requires 
Peroxide of manganese (mixed) 9.61 Oxygen-ratio. 
Peroxide of manganese (combined) 52.80 contains O 19.36 4 
