332 M. E, Mitscherlich on 



of potash containing 0*6077 gr. potash. Hence, 100 parts 

 of hypermanganate of potash contain 



Oxygen, 



Hypermanganic acid, . .71* 35*2 



Potash, 30-135 5-1 



The oxygen of the potash is, therefore, to thai of the acid 

 in this experiment as 1 : 69, whence, it follows that the 

 true proportion is as 1 : 7. The composition of the hyper- 

 manganate of potash calculated after these data, is 

 Hypermanganic acid, . . 70*53 



Potash, 28*47 



Several experiments, which were made before I determined 

 the best method, agreed very nearly with this result. 



The hypermanganate of potash is little soluble in water, 

 1 part requiring, at 59° F., 16 parts of water to dissolve it. 

 All the other salts of this acid are much more soluble, 

 except the hypermanganate of silver, 1 part of which dis- 

 solves in 109 of water. I have not observed any insoluble 

 salt which it forms. Hypermanganic acid has so great an 

 affinity for potash, that it will, when combined with it, 

 unite with no other base by double decomposition. For 

 example, a solution of hypermanganate of potash may be 

 mixed with a solution of chloride of barium, and the mix- 

 ture evaporated. The hypermanganate of potash will 

 crystallize along with the chloride of barium without any 

 interchange of the acids taking place. Hence, the salt 

 which hypermanganic acid forms with oxide of silver is 

 the only one convenient for combining it with other bases. 



If a warm solution of nitrate of silver be added to a warm 

 solution of hypermanganate of potash, the hypermanganate 

 of silver separates as the solution cools, in large, beautiful, 

 easily measurable crystals. These crystals may be dis- 

 solved in water and re-crystallized, but the solution must 

 not be boiled, or it will be decomposed, which does not 

 happen if it be cautiously evaporated. 



By means of the hypermanganate of silver the other 

 salts of this acid may be formed, by adding to the crystals 

 of this salt as much of the solution of any chloride as is 

 necessary to decompose them. The crystals must previously 

 be reduced to a fine powder, and they must be stirred for a 

 long time with the solution of the chloride. The chloride 



