166 On alloying Iron with Manganese.., 



Should further experiments confirm the existence of the pnis- 

 sic acid in bread made from the new flour, the fact would in 

 some measure serve to accoint for the injurious effects that have 

 been attributed to it, especially when freely used by children. 



Cork, .laii. 20, 1817. ' Edm'uND DaVY. 



XLI. On alloying Iron with Manganese. By David Mushet, 

 Esq. of Colcford, Forest of Dean. 



To Mr. Tilloch. 



Dear Sir, — i. he general result of my two last communication* 

 showed that there existed a difficultv in combining to any con- 

 siderable amount the metal of manganes^e with that of iron, 

 either bv the fusion of c^st-iron with the ore of manganese, or 

 by the fusion of the ores of both metais. Nothing favourable 

 to a |7ractical result in the blast-furnace could be inferred, par- 

 ticularly it it were necessary to unite manganese to the extent 

 of 20 or 30 per cent, with the metal of iron for any particular 

 object of manufacture. It was however remarked, that while 

 the metallic results or buttons were ol^edient to the magnet, some 

 minute spherules of metal were obtained, over which it had no 

 influence. I therefore concluded that the difficulty arose from 

 .1 defective mode of operation, and that those circulnstances ne- 

 cessary to produce de-oxidation and reduction in ores of iron 

 were not sufficient to produce a similar effect when an ore 

 of manganese was operated upon. In the blast-furnace as well 

 as in the assay-furnace |>revious de-oxidation is necessary to 

 metallic reduction. In the former this is completely effected by 

 a process of cementation which takes place in the upper regions 

 of the furnace. In the latter, the fusion being more rapid, the 

 effect is generally produced by the presence of a quantity of 

 carbonaceous matter in the mixture. If the crucible is formed 

 of a mixture of clay and this latter substance, the fusion will ad- 

 mit of a more rapid progress, and the oxidation and reduction 

 will be more completely effected. Hence in the reduction of 

 ores of iron in crucibles formed of clay and blacklead, metallic 

 masses of iron may be ol^tained so highly saturated with car- 

 buret of iron as to destroy metallic weight and compactness : 

 under such circumstances the most perfect de-oxidation takes 

 place; no vestige of iron remains unrevived, or the slightest trace 

 of its oxide in the glass. Considering the use of such crucibles 

 favourable to the reduction of manganese, I determined on at- 

 tempting the alloy of this metal with iron to a greater extent 



than 



