By emnparing these forlnulas widl those of the bromine and ammonia process, I think a pretty clear view may be had of" the different conditions of" the two methods, without further comment.
After what has,just been shown, there is no disguising the Fact tha) the bromine and ammonia process is more rapid and convenient than the process with fixed alkaline salts ; but it sh()uhl be here pointed out that a great mistake is often committed in saying that it is iml)ossible to free the 1)recipitate from alkali by washing. Professor Eggertz has stated that by means of cold water containing one per cent. of hydrochloric aeid the precipitate may be e'tsilv freed from alkali. In Germany, where the fixed alkali method is used, this mode of' washing is not so frequently known a~ might be supl)ose(1 , and at one works i[ was told that experience went to show that 115 using chh)rine instead of bromine the washing of the t)reeit)itate with ordinary hot water could be more easily eitbcted.
When chlorine is used fbr precipitating tile manganese, no amlnoniacal salts must be present~ otherwise the explosive compound ClaN may be formed. ()n the other han(1, in the (~ase of bromine and ammonia, no explosion need be feared.
Tile diflhrent methods, ()f which the outlines have now 1)ceu given, yield quite coneordallt results when carried out by experienced hands~ and for rail-steel there is certainly no preferem.e 1() I)e given to any of them so ihr as accuracy goes. According to my own working, the results should not vary more than 0"05 per cent. and the time required {'or an estimation one day; ot' course several '~ssays can be made at the same time. As to rapid}u, the bromine and ammoida process will no doubt prove the best, ibr reasons stated above.
There are many volumetric methods for determining nlanganese, but, as fi~r as ] have seen, none is more ral)id than the gravimetri(, method with bronfine and ammonia.
A new volumetric method has been recently devised in the Stockhohn S(qm()l of Mines and will shortly he published.