1817 



througli the mixture in the Hask for one hour, after which a rapid 

 filtration witli 2 g. of kiezelgiir through a pleated filter gave a clear 

 filtrate. 



175 c.c. of this liquid were iiiti-oduced into a similar louiid bot- 

 tomed flask, closed by a rubber stopper, carr^'ing two glass tubes, 

 one of which, reaciiiiig to the bottom, admitted the carbonic acid, 

 while the second short one was connected with a tidje, filled with 

 10 c.c. of H,SO< 3^ N, to allow an estimation of the ammonia, which 

 might have been blown over. 



After saturation with carbonic acid the current was stopped, the 

 controlling tube with 11,80^ was exchanged for another, the 

 stopper of the flask was lifted a moment and 25 c.c. solution, con- 

 taining I g. of' urea were (piickly introduced. This solution had been 

 brought before to 27° in the same bath. After replacing the stopper 

 and again admitting the carbonic acid the reaction was allowed to 

 proceed at constant tem[)eralure and constant j>fj and its progress 

 measured from time to time bv interiupting the current of carbonic 

 acid for a moment, taking out a sample of 5 c.c. with a pipette 

 and running this quickly into 25 c.c. of H^SO^ ^ N. After dilution 

 with some water the contents of this flask were boiled to expel the 

 carbonic acid and titrated with NaOH -^ N and lacmoid (or later 

 with Sodium alizarin sulphonate) as indicator. Owing to phosphate 

 and proteins of the Soja, this titration was not very sharp, leaving 

 an uncertainty of one or two drops of NaOH -^ N. 



30 60 90 120 150 180 210 

 Minutes. 

 Fig. 5. 



