ON MANGANESE 67 



SECTION XXII. 



All this appears still more clearly with phlogisticated 

 nitrous acid. The manganese decomposes this acid for the 

 same reason as it does the volatile sulphureous acid (Sec. xx.). 

 That the phlogiston of the acid really combines with the 

 manganese appears from this, that on adding to such a 

 solution some vegetable acid, there is no smell of aquafortis 

 observed (Sec. xvn.), and the distillation with pure vitriolic 

 acid yields limpid, by no means yellow, nitrous acid. There 

 appears no effervescence here, as happens with the solution 

 in pure nitrous or vitriolic acids, on adding a little gum or 

 sugar (Sec. xvi. (a)). It is well known that a great quantity 

 of aerial acid is constantly developed in the decomposition of 

 any animal or vegetable substance. Now, since manganese, 

 assisted by acids, has the same effect upon those substances 

 as air and other bodies have, which extract from them their 

 phlogiston, there must necessarily be in this process a 

 separation, or perhaps a generation of aerial acid. But, 

 in the present case, with phlogisticated nitrous acid, no 

 such effervescence can take place, because it is combined 

 with pure phlogiston ; and if this be again separated, I do 

 not see why aerial acid should be extricated. Moreover, 

 manganese, when united with nitrous acid and metals, 

 arsenic or oil of turpentine, is entirely dissolved without 

 showing any effervescence. 



SECTION XXIII. 



The sixth paragraph shows the effects of muriatic acid. 

 In this case, perhaps, it does not immediately appear whence 

 manganese should obtain its phlogiston ; no phlogiston being 



