ON MANGANESE 69 



mark of aerial acid, only a very sensible pungent smell, 

 highly oppressive to the lungs, and resembling the smell of 

 warm aqua regia. The solution in the retort was clear and 

 of a yellowish hue, which was owing to the iron contained 

 in it. If you wish to be convinced that the manganese, 

 thus dissolved, likewise contains phlogiston, you should 

 precipitate the solution with alkali of tartar, edulcorate 

 the precipitate, and treat it in the manner above mentioned 

 (Sec. xvi. (a), (5), (c)). But whence did it acquire its phlogiston ? 

 From the muriatic acid. The matter of heat has no share 

 here, because the solution becomes limpid without it, if it 

 be only exposed to the air for a few hours. The following is 

 the theory of the solution : The manganese is first attacked 

 by the acid, and thus we have a brown solution. The 

 manganese, when dissolved, acquires, by means of the acid, 

 a strong attraction for phlogiston (Sec. xiv. (2)), and 

 really attracts it from the particles with which it is 

 combined. These particles having thus lost one of their 

 constituent parts, and being but very loosely combined with 

 the phlogisticated manganese, are expelled from it by the 

 remaining muriatic acid, which has not yet suffered any 

 decomposition, and now appear with an effervescence as a 

 highly elastic air; the brown colour has now disappeared, 

 and the solution is become limpid. 



SECTION XXIV. 



The marine acid separated from phlogiston, one of its 

 constituent parts, unites with water in a very small quantity 

 only, and gives it a slight acid taste ; but whenever it is 

 enabled to combine with phlogiston, it assumes its former 

 nature, and again becomes a true muriatic acid. In order 

 to discover the properties of this aerial tiuid, it is best to 



