TITRATION AND ADJUSTMENT OF CULTURE MEDIA 



213 



of phenolphthalein had been added. While stirring the mix- 

 ture, deci-normaP soda solution from a burette was run in with- 

 out any heating whatever. The end point taken was the first 

 delicate pink tinge, observable throughout, which did not dis- 

 appear after stirring the solution — and should not disappear for 

 at least one minute. The figures were then recorded. The cas- 

 serole with the mixture was then set over the flame, brought 

 to a boil and boiled one minute by the watch. 



Outline of Experiments 



= preliminary boiling of 30 min. 

 = preliminary' boiling of 60 min. 

 = preliminary boiling of 120 min. 



preliminary boiling of 30 min. 

 preliminary boiling of 60 min. 

 preliminary boiling of 120 min. 



preliminary boiling of 60 min. 

 preliminary boiling of 120 min. 



Bi 60 C 

 Bi 120 C 



preliminary boiling of 60 min. 

 preliminary boiling of 120 min. 



preliminary boiling of 30 min. 

 preliminary boiling of 60 min. 

 preliminary boiling of 120 min. 



preliminary boiling of 30 min. 

 preliminary boiling of 60 min. 

 preliminary boiling of 120 min. 



Corrected t o 

 plus one ac- 

 cording to 

 room tempera- 

 ture titration 

 after each au- 

 toclaving. 



Cor rected to 

 plus one ac- 

 cording to boil- 

 i n g tempera- 

 ture titration 

 after the first 

 autoclaving. 

 No further ad- 

 justments 

 were made be- 

 cause of error 

 in adding too 

 much soda. 



Corrected to 

 plus one ac- 

 cording to 

 boiling tem- 

 perature titra- 

 tion after each 

 autoclaving. 



