32 



Brown — Hydrochloric Acid and Potassium 



sium permanganate and hydrochloric acid is removed during 

 the digestion. When also the chlorine is thus removed the 

 same quantity of permanganate is required to bring about final 

 coloration whether ferric chloride is present or not. It is found 

 also that the permanganate is entirely destroyed within the 

 limits proposed by Wagner, and that after an hours digestion, 

 and in fact long before, the permanganate color has entirely 

 disappeared and only thehydrated oxides of manganese, formed 

 according to the Guyard reaction, are visible in the digestion 

 liquid. 



Wagner describes no special form of apparatus in his work, 

 and gives no details as to size of flask used to contain the diges- 

 tion liquids, form of bath, etc., pointing out the fact simply 

 that he used a return-condenser 60 cm in length. It was found 

 convenient in the experiments about to be described to use a 

 250 ctoI flask to contain the solutions during digestion, and to 

 heat the solutions in an Ostwald thermostat. 



Table I. 



[9-91 cm8 H 2 C 2 4 = 20-25 cm3 KMn0 4 ] 



















KMn0 4 



~HC1 



N 

 W HC1 



N 



KMn0 4 

 before 

 diges- 



Tem- 

 pera- 



Time 

 diges- 

 tion. 



N 

 ^j-H 2 C 2 4 



KMn0 4 

 to color. 



apparently- 

 reduced 

 during- 



cm 3 . 



cm 3 . 



cm 3 . 



tion. 



ture 



cm 3 . 



cm 3 . 



digestion. 









cm 3 . 



C°. 



min. 







cm 3 . 



100 



991 





991 



50 



60 



9-91 



' 15-89 



5-55 



100 



9-91 





9-91 



t i 



" 



9-91 



15-11 



4-77 



100 



9-91 





9-91 



" 



a 



9-91 



15-15 



4-81 



100 



9-91 







991 



u 



" 



9-91 



15-07 • 



4-73 



100 



9-91 







991 



a 



" 



9-91 



15-13 



4-79 



100 



9-91 





9-91 



" 



a 



9-91 



15-07 



4-73 



100 



991 







9-91 



it 



" 



9-91 



15-08 



4-74 



100 



991 





9-91 



a 



a 



991 



15-02 



4-68 



100 



9-91 





9-91 



a 



a 



9-91 



14-85 



4-51 



100 



9-91 







9-91 



a 



a 



9-91 



14-40 



4-06 



100 



991 



... 



9-91 



a 



a 



991 



15-05 



4-71 



100 





9-91 



9-91 



« 



ii 



9-91 



15-60 



5-26 



100 







9-91 



9-91 



" 



i i 



9-91 



15-35 



5-01 



100 





9.91 



9-91 



it 



it 



991 



15-32 



4-98 



100 





9.91 



9-91 



" 



a 



9 91 



15-88 



554 



100 







9-91 



9-91 



a 



a 



9-91 



15-42 



5-08 



100 







9-91 



9-91 



a 



a 



991 



15-45 



5-11 



100 







9-91 



9-91 



it 



a 



9-91 



15-95 



561 



100 





991 



9-91 



it 



a 



9-91 



15-41 



5-07 



100 







991 



9-91 



a 



a 



9-91 



15-95 



5-61 



100 





9-91 



9-91 



a 



a 



991 



16-65 



6-31 



100 







9-91 



9-91 



a 



a 



9-91 



15-75 



5-41 



100 



__. 



9-91 



9-91 



a 



u 



9-91 



15-79 



5-45 



The experiments of Table I were conducted, as outlined by 

 Wagner, in the following manner : To a 250 cm3 flask were added 

 100 cml of normal hydrochloric acid (that is a solution contain- 



