354- Dr. Wackenroder's Mineralogical and Chemical 



c. The solution having been copiously diluted, was mixed 

 first, in the cold, with carbonate, and then with bicarbonate of 

 soda, in order to separate the oxide of iron and alumina. The 

 precipitate was then slightly heated, and again dissolved in 

 concentrated muriatic acid. There remained a small quantity of 

 silica, which after having been heated, weighed 0*002 gramme, 

 and remained unaffected even after a continued digestion in 

 sulphuric acid. 



d. The solution of iron in (c) was abundantly mixed with 

 caustic potash, and the precipitated hydrate of iron separated 

 and slightly heated. The 0*0701 gramme of pure oxide of iron 

 calculated for protoxide, in which state the iron evidently exists 

 in the mineral, give 0*6029 gramme of protoxide, if the equiva- 

 lents of the two oxides bear the proportion to each other of 

 39 to 35. 



e. Carbonate of ammonia, with heat, precipitated from the 

 solution (d) 9 which had been saturated with muriatic acid, the 

 alumina contained in the mineral ; which, after the burning of 

 the filtre that had been used to separate it, and after deduct- 

 ing the ashes of the latter, consisted of no more than 0*005 

 gramme. 



f. In order to separate the manganese from the liquid (e) 

 which had been treated with carbonate of soda, I made use of 

 the method lately pointed out by Counsellor Stromeyer*. Ac- 

 cordingly the solution, in consequence of the small quantity 

 of manganese it contained, was first reduced by boiling to a 

 smaller bulk, saturated with chlorine gas, and then mixed 

 with as much neutral carbonate of soda as was necessary to 

 precipitate the deutoxide of manganese, and render the solution 

 colourless. The precipitate having been dried off for forty- 

 eight hours, and then collected on a filtre and heated, amounted 

 to 0*0027 gramme of deutoxide of manganese, which, according 

 to the equivalents, 39*17 for the deutoxide, and 36*5 for the 

 oxide, indicate 0*0025 gramme of the latter, it being requisite 

 to assume that the manganese is in this state of oxidation in 

 the mineral. 



g. The solution having been again concentrated by boiling, 

 it was mixed with as much oxalate of potash as was necessary 

 to precipitate the lime ; and the precipitate separated as soon 

 as possible by filtering, its separation having been promoted 

 by a small addition of oxalic acid. The oxalate of lime ob- 

 tained was made red hot, in order to destroy its acid, 

 again dissolved in nitric acid ; and the solution mixed with 

 caustic ammonia freed from carbonic acid, gave a slight pre- 



* Gotting. Gelehrte Anzeigen. St. 158. October 1827. 



cipitate. 



