§ 126. MISCELLANEOUS DETERMINATIONS. 247 



concentrated hydrochloric acid, and filter. By mixing this 

 filtrate with that obtained in 3, the excess of silver is pre- 

 cipitated, and may be removed from the solution by fil- 

 tration. 



5. Treat the residue, insoluble in hydrochloric acid, as 

 directed in § 58, a, 3, for the separation of silica, sand, 

 and coal. 



6, Eliminate the silica in the hydrochloric solution fil- 

 tered from the excess of silver in 4, in the usual manner 

 (§ 58, «, 1), and examine the filtrate from the silica ac- 

 cording to Scheme III. or lY., § 94, according to whether 

 mans^anese is or is not to be determined. 



126. Statement of results. — So much sodium as is nec- 

 essary .to combine with all the chlorine should be consid- 

 ered as so combined, while the remainder of the sodium is 

 given as sodic oxide. 



If there is not sodium enough for this purpose, take 

 enough of the potassium to combine with what chlorine 

 is left, and give the remainder of the potassium as potassic 

 oxide. 



The manganese is to be given as manganous manganic 

 oxide, MUgO^. 



The sand and coal are accidental ingredients of the ash, 

 and therefore the percentage composition should be calcu- 

 lated with reference to what is left after subtracting these 

 from the weight of ash taken for analysis. 



The percentage composition should moreover be given 

 with reference to the remainder left after subtracting the 

 carbonic acid also, since this is not properly one of the 

 mineral substances found in the plant, but results from the 

 combustion of the organic acids. 



The first statement enables one to judge of the accuracy 

 of the analysis, and the second gives the real composition 

 of the mineral matter found in the particular plant exam- 

 ined. 



