HOW — -ON ORES OF MANGANESE AND THEIR USES. 1-35 



very small pieces, varying in size from that of a pea to a small onion ; 

 it is compact, very black, and does not show the crystal as ours does. 

 There is iron ore, said to be very pure, taken out of the deposit, and an 

 ochre largely charged with oxide of iron. The process of obtaining and 

 cleaning the manganese is slow and must be expensive : they wash it in 

 pans by a process something similar to that adopted here for the separa- 

 tion of gold from powdered quartz. The quantity of manganese at the 

 Brandon mines is very sinall in proportion to the amount of material 

 operated on compared with ours. The Brandon manganese is very pure 

 when thoroughly cleansed, but this is a difficult matter as the oxide of 

 iron adheres tenaciously." 



Uses of Manganese Ores. — These ores are employed for a variety 

 of purposes in certaiu mainifactures of purely chemical character, 

 or in Avhich the aid of chemistry is neeessa]-y, and according to the 

 application to be made of them they are required of different 

 degrees of purity : in most cases a tolerably high percentage of 

 the particular oxide of manganese, called the binoxide, peroxide, 

 or available oxide, is necessary, and for certain uses there must be 

 little else in the ore, and especially iron must be either absent or 

 present in extremely small proportion. The manufactures in which 

 the ores are used are principally those of bleaching powder, glass, 

 pottery, ia^on, some brown colours used in dyeing, and manganates 

 and permanganates for certain oxidizing processes (as bleaching fats) 

 and for disinfecting. The native oxide is used for making boiled 

 oil, and has also been recommended as a deodorizer and purifier of 

 water, and a cheap agent for extracting gold from quartz. 



It is perhaps impossible to learn the total consumption of the 

 ore for these purposes ; we know, however, that Great Britain is 

 the great seat of the chemical manufactiu-es, and we have some 

 facts to guide us to an estimate of the amount used there in the 

 processes requiring the largest quantity ; these I A\ill now give, 

 together with a rough estimate of the consumption in the United 

 States. The most extensive use of the ore is in the making of 

 bleaching powders (chiefly chloride of lime). According to the 

 report previously quoted, the amount of manganese imported into 

 the Tyne district alone for this purpose was then (I860) given as 

 11,400 tons per annum, at £4 stg. per ton. Although this district 

 is a very considerable seat of chemical manufactures, there are 

 other parts of the Kingdom where very large quantities of manga- 

 nese are required, among which, the most important are Liverpool, 



