Muffle furnaces are suitable for fine ores which are liable to decrepitate or sinter.
The process is effected either in heaps, stalls, shaft furnaces, reverberatory furnaces or muffle furnaces.
These burners, or modifications of them, have also been applied to muffle furnaces, which are convenient when only a few assays have to be made - the furnace being a mere clay shell and soon brought to a working temperature; but the fuel is too expensive to allow of their being used habitually or on a large scale.
The precipitate is collected in a filter-press, and then roasted in muffle furnaces with nitre, borax and sodium carbonate.
These do not hunt in packs, but will sometimes singly attack a bullock; they and the wolves make havoc among sheep. A favourite feat of the boldest of the young men of southern Afghanistan is to enter the hyena's den, single-handed, muffle and tie him.