ON MANGANESE 63 



that this acid dissolves the manganese entirely without the 

 addition of any phlogiston. It would be difficult to compre- 

 hend whence the phlogiston in this case should come, if we 

 were not certain that several substances, which have a great 

 attraction for phlogiston, can attract it in a red heat. 

 Quicksilver, and silver when dissolved in the purest nitrous 

 acid, really lose the phlogiston (Sec. iv.) which is a con- 

 stituent part of these metals. This appears from the red 

 vapours under the form of which the nitrous acid arises ; 

 and the dissolved metallic earth cannot be again reduced to 

 its metallic form till it has again acquired the lost phlogiston, 

 which is effected either by precipitation with complete metals, 

 or else by means of heat alone. It is known that nitrous 

 acid, when combined with a little phlogiston, adheres after- 

 wards to absorbent bodies so loosely that it may be expelled 

 from them by vegetable acids. If a small glass retort filled 

 with nitre is kept upon the fire till the nitre shall have been 

 in a red fusion for half an hour, it is found, after cooling, 

 to have acquired some phlogiston. For, when rubbed with 

 tamarines, a strong smell of aquafortis rises ; and it likewise 

 deliquesces in the open air, though there is no mark of any 

 superabundant alkali. And what else can be the cause, that 

 fuming nitrous acid, when distilled, rises at last, when the 

 retort is nearly of a white heat, in blood-red vapours, whereas 

 it ascends during the distillation in a limpid form like water ? 

 I could adduce many more experiments to prove that 

 phlogiston is contained in fire, if I was not afraid of rendering 

 this dissertation too long. This, however, I may add, that the 

 following objection is void of foundation : Why, if what I 

 assert was really the case, the calxes of the ignoble metals 

 are not equally reducible by heat ? since all bodies have not 

 an equal degree of attraction to phlogiston. 



Thus manganese can attract the quantity of phlogiston 



