Manganese, Black Oxide Binoxide

Manganese —Binoxide of Afawymiese—MnOj.—One of the commonest ores of mangoncse is found in a state of great purity in Sweden and other parts. The purest variety is that known in commerce under the term of pyrolusits, or black oxide of manganese. 

Dissolve 16 parts gum-arabic in the least possible quantity of water, and mix with it 9 parts phosphorus iu powder (see No. 4338) then add 14 parts nitre (saltpetre), and 16 parts of either vermilion (red sulphuret of mercury), or binoxide (black oxide) of manganese, aud form the whole into a paste. Dip the matches into this pasto, and then let them dry. When quite dry they are to be dipped into a very dilute copal or lac varnish, and again dried by this means they are less likely to suffer from damp weather. 

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