ON MANGANESE 57 



the mixture of nitrous acid and manganese, (d) The other 

 half was evaporated, and some small angular shining crystals 

 were obtained, which, with regard to their crystallisation, 

 agreed with those obtained by the nitrous acid. 



SECTION VII. EFFECTS OF FLUOR ACID. 



But very little of the manganese, after being digested 

 with this acid for several days, was dissolved ; and it was 

 necessary to add a very large quantity of levigated manganese 

 before the acid was saturated. The solution had hardly any 

 sensible taste ; a little precipitation took place on adding 

 alkali. But if a neutral salt, composed of this acid and 

 volatile alkali, be added to the solution of manganese in any 

 one of the above-mentioned acids, a double decomposition 

 takes place, and the manganese, uniting with the fluor acid, 

 is precipitated. 



SECTION VIII. EFFECTS OF PHOSPHORIC ACID. 



1 drm. of phosphoric acid being boiled with half a drachm 

 of powdered manganese, dissolved but little of it; and, 

 though evaporated to dryness, the remainder had a very 

 sour taste. At last, however, by adding more manganese, 

 the acid was saturated. On adding microsmic salt to a 

 solution of manganese, a decomposition follows like that 

 effected by the fluor acid. 



SECTION IX. EFFECTS OF ACID OF TARTAR. 



Pure acid of tartar, digested in the cold with manganese, 

 produced a brown solution ; but, on digesting in heat, more 

 was dissolved with a kind of effervescence; the whole 



