HOW ON ORES OF MANGANESE AND THEIR USES. 137 



limited, perhaps a few hundred tons a year are fully as much as 

 would find sale at the highest prices named. That there is always 

 a steady demand for ore useful for making bleaching powder, is 

 shown by the efforts made to restore to its original state the oxide 

 employed : patents have been taken out for this purpose, and 

 one is recommended by its owner as restoring the material to 

 52 per cent, and as beiiig capable of bringing it up to TO per 

 cent, binoxide, which, as we have seen, is a very moderate per- 

 centage in the ores. 



With regard to the other applications of manganese, the making 

 of iron and steel is the most important. Manganese renders iron 

 tough and steel better and more durable, in the latter case it acts 

 by removing sulphiu" and silicon. Although the quantity of man- 

 ganese actually imparted to the iron and steel is very small, in a 

 manufacture of such enormous proportions the consumption must 

 be large if continued. The making of manganates and per-manga- 

 nates, which are used as oxidizing agents and in disinfecting, must 

 also be extensive, a prize medal having been given to Mr. Condy 

 in 1862 for the manufacture of such salts on the large scale. 



As an illustration of the way m which the ores are sometimes 

 treated in practice, I may mention the mode adopted by Mr. Hobbs, 

 of Boston, who has had a great deal to do with the Upham and 

 Shepody ores of New BrunsAvick. The ore is washed clean at the 

 mines, boxed up, and sent to Boston, when it is selected into three 

 good qualities and refuse ; the three good sorts are ground in three 

 mills till fine as flour, put up in barrels papered inside, and the 

 contents of each barrel are assayed and sold according to assay. 



The first quality free (?) of iron and containing about 98 per 

 cent, of peroxide of manganese, is used for making the finest (flint) 

 glass. The second quality (also no doubt pretty free of iron), con- 

 taining from 75 to 80 per cent, peroxide, is used for making white 

 phials. The third, containing about 70 per cent, peroxide, is em- 

 ployed for making common glass bottles ; while the refuse, contain- 

 ing perhaps 25 or 30 per cent, iron, is used either in making clear 

 amber coloured bottles for brandy, etc., or for carboys. 



In conclusion I state together the quantities of binoxide of 

 manganese contained in some of the Nova Scotian ores, as found 

 by the experiments of my pupils or myself: — 

 16 



