34 



Brown — Hydrochloric Acid and Potassium 



remove if possible this chlorine, and to this end a vigorous cur- 

 rent of carbon dioxide or air was passed through the digestion 

 liquid while heating. In this way the chlorine was readily 

 removed and starch and potassium iodide paper held in the 

 current of carbon dioxide or air gave no test for chlor- 

 ine. 



The experiments of the following table (II), in which no fer- 

 ric chloride was used, were conducted precisely as were those 

 of Table I above, except that a vigorous current of carbon dioxide 

 generated in a Kipp generator by action of hydrochloric acid on 

 marble, and washed and dried by passing first through a bottle 

 filled with water and then through a calcium chloride tube, 

 was passed through the liquid during the process of digestion. 

 Because also of the greater ease of measuring out accurately 

 9*90 cm3 rather than the 9'91 cm3 used by Wagner and in the experi- 

 ments of Table I above, the former volume of reagents was sub- 

 stituted for the latter in the experiments to follow. It will 

 readily be seen that in the case of tenth normal hydrochloric 

 acid O01 cm3 is negligible as compared with the large amount of 

 hydrochloric acid used in the experiments. 



The results of these experiments are recorded in Table II. 



Table II. 



^HCl 



N 

 10 

 cm 



HC1 



KMn0 4 

 before 

 diges- 

 tion. 

 cm 3 . 



Tem- 

 pera- 

 ture. 

 0°. 



Time 



of 

 diges- 

 tion, 

 min. 



H2C2O4 

 cm 3 . 



KMn0 4 

 to color 



KMn0 4 

 appar- 

 ently 

 reduced 

 during 

 digestion. 

 cm 3 . 



[9-90 cm3 approximately ^ H 2 2 0, 



=23-52 cm3 KMn0 4 ] 



I 



100 



9-90 



9-90 



50 



60 



9-90 



22-19 



8-57 



II 



100 



9-90 



9-90 



" 



i t 



9-90 



22-10 



8-48 



III 



100 



9-90 



9-90 



4i 



u 



9-90 



22-15 



8-53 



IV 



100 



9-90 



9-90 



a 



u 



9-90 



22-11 



8-49 



N 





[9-90 cm3 approximately ^ H 2 C 2 4 = 



= 23-65 cm 



3 KMn0 4 ] 





V 



100 



9-90 



9-90 



50 



60 



9-90 



2215 



8-40 



VI 



100 



9-90 



9-90 



" 



" 



9-90 



21-79 



8-04 



VII 



100 



9-90 



9-90 



n 



a 



9-90 



22-24 



8-49 



VIII 



100 



9-90 



9-90 



a, 



a 



9-90 



22-21 



8-46 



IX 



100 



9-90 



9-90 



n 



a 



9-90 



22-24 



8-49 



X 



100 



9-90 



9-90 



a 



n 



990 



22-23 



8-48 



XI 



100 



9-90 



9-90 



c i 



" 



9-90 



22-25 



8-50 



XII 



100 



9-90 



9-90 



11 



" 



9-90 



22-15 



8-40 



XIII 



100 



9-90 



19-80 



a 



a 



9-90 



19-77 



15-92 



XIV 



100 



9-90 



19-80 



a 



t i 



9-90 



19-83 



15-98 



XV 



100 



9-90 



50-0 



a 



a 



25-00 



44-53 



34-81 



XVI 



100 



9-90 



50-0 



a 



" 



25-00 



44-47 



34-75 



XVII 



100 



9-90 



50-0 



lt 



a 



25-00 



44-44 



34-72 



XVIII 



100 



9-90 



50-0 



it 



a 



25-00 



44-58 



34-86 



