

ON MANGANESE 95 



presence of phlogiston in heat (Sec. XVIL). It seems as if 

 the black powder was nothing else but calx of lead, which, 

 having lost its phlogiston entirely, or for the most part, 

 during a gentle and slow calcination, has thus acquired such 

 a strong tendency to unite again with it, as to be able to 

 decompose muriatic acid. 



SUPPLEMENT TO THE FOREGOING DISSERTATION ON 

 MANGANESE. BY T. BERGMAN. 



Mr. Scheele, after having examined the composition of 

 fluor, undertook, at my request, the examination of manganese, 

 and has offered to the Society what he has learned upon the 

 subject by his numerous and ingenious experiments, which 

 were continued during the space of three years. After he 

 had finished these experiments, I informed him that Mr. 

 Sage supposes manganese to be nothing else than a mineralised 

 mixture of cobalt and zinc. He immediately made several 

 experiments for this purpose, but found not the least mark 

 of either of those metals. 



Manganese has been classed by all mineralogists among 

 the iron ores: Mr. Pott, however, thought the iron to be 

 mixed only accidentally ; and at last Mr. Cronstedt, in his 

 Essay on Mineralogy 1758, placed it among the earths. For 

 my part, however, I must own there are several circumstances 

 which make me think that it is a metallic substance. 



No pure earth colours glass ; but all metallic calxes have 

 this property. Manganese, therefore, in this respect shows 

 a great resemblance to the latter, which is further increased 

 by its specific gravity, and its strong attraction for phlogiston. 

 But what principally confirms me in my conjecture, is the 

 following experiment, which I made with a view to determine 

 its nature more particularly. It is well known that fixed 



