ANALYSIS OF CARNALUT, KAINIT, ETC. 551 



flask is filled to the mark with water, well shaken, and its con- 

 tents filtered. Fifty cubic centimeters of the filtrate are treated in 

 a 200 cubic centimeter flask with a solution of barium chlorid, 

 the flask filled to the mark, well shaken, and its contents filtered. 

 Twenty cubic centimeters of the filtrate, corresponding to 0.3571 

 or 0.3056 gram of the substance, as the case may be, are treated 

 with five cubic centimeters of platinic chlorid solution and the 

 potassium estimated according to the usual methods. When the 

 perchloric acid method is employed, 13.455 grams of the carnallit 

 or bergkieserit, or 15.7225 grams of kainit, sylvinit or hartsalz 

 are dissolved in a 500 cubic centimeter flask and treated directly 

 with barium chlorid. Twenty cubic centimeters of the filtrate, t 

 equal to 0.5382 or 0.6289 gram of the sample, as the case may 

 be, are then treated with perchloric acid, as described further 

 along. 



(3) Estimation of Potash (K 2 O) in Raw Potash Salts. (a) 

 For the determination of potash alone in carnallit, kainit, and syl- 

 vinit 100 grams of the well-mixed sample are put into a grad- 

 uated flask holding one liter and dissolved by boiling with half 

 a liter of water, acidulated with 10 cubic centimeters of hydro- 

 chloric. The purpose of adding hydrochloric acid is to bring 

 any polyhalit that might be present in the salts into solution and 

 which it is difficult to dissolve in pure water. After dissolving 

 and cooling, the flask is filled up to the mark. The solution, 

 after mixing, is filtered through a dry filter and 100 cubic centi- 

 meters of the filtrate, corresponding to 10 grams substance, are 

 put into a half liter flask by means of a pipette. After the addi- 

 tion of 200-300 cubic centimeters of water the solution is heated 

 to boiling and the sulfuric acid accurately precipitated with nor- 

 mal barium chlorid solution, containing 104 grams of the dry 

 salt in one liter. The volume of the precipitate is calculated from 

 the amount of barium solution used and from the specific gravity 

 of the barium sulfate. After cooling, the flask is filled up with 

 water as far above the mark as equals the volume of the calcu- 

 lated barium precipitate, and, after thorough mixing, the solu- 

 tion is filtered again through a dry filter. Fifty cubic centi- 

 meters of this filtrate, corresponding to one gram substance, are 



