432 PROFESSOR HEDDLE ON 
It has to be kept in view that, under the concentrated energy obtainable in 
close cavities, and with the larger amount of alkalies which the wnaltered 
mineral would contain, the amount and ease of the liquefaction must have been 
more complete. 
Psilomelane. 
The massive sub-fibrous variety was that analysed. 
8. G. 4° 607 
Manganous Oxide, F 66°995 = 71°868 MnO,Mn,0,. 
Cobalt Oxide, : : ; F 1°478 
Magnesia, . : : : ; °098 
Baryta, i : f d ‘ 14°876 
Potash, : : A , : 5 
Soda, . : : } : : *003 
Oxygen, . ’ ; ' : 6°712 6°658, 
Water, : i ; ; : 6 205i: 6 °003 
101° 484 
Hygroscopic Water, é f 1-+201 per cent. 
Heated barely red, lost . : 6°051 of water. 
» bright red, : 2 1: 066 of oxygen. 
» toa white heat, . : 5 ‘646 more. 
Cavities in this psilomelane are rarely covered with a velvet coating of 
mangansammat-ere. 
The wad which occurred as a vein of about two inches in thickness, of a 
blue-black colour, and brown streak, was analysed. When steeped in water a 
considerable quantity of a saline efflorescence exudes from it ; as the specimen 
had been washed, some of the alkalies must have been thus lost. 
8. G. 4:4, 
This yielded— 
Manganous Oxide, F P ’ 64°87 = 69:58 MnO,Mn,0,. 
Cobalt Oxide, . ; ; ; 1:°995 
Magnesia, . 3 § : ‘ -199 
Baryta, : 4 : ; : 14:97 
Potash, a : ; f b ‘247 
Soda, . : ; ; ’ ; * 259 
Alumina, . ; F F : 1:097 
Silica, : , : ; *898 
Oxygen, ‘ , ; : : 5 S211 
Water, aH : ; P 5 +688 
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