206 Hydrolijds of the Soluble Protein of Swede Turnips 



separated, making a total weight of 37-014 grms. This leaves a weight 

 of 67-5 - 37-014 = 30-486 grms. for the weight of the vahne. The 

 weight of acids unaccounted for is 30-486 — 28-68 = 1-806 grms. This 

 loss was caused probably by the large number of recrystallisations 

 which were necessary for the satisfactory separation of the amino-acids. 

 28-68 grms. of vahne correspond to a percentage of 



J—-—— = 9-95 of valine in the protein. 

 288-08 



Fraction 3. As'partic acid. 



The esters, after extraction of phenyl alanine ester, were saponified 

 by boihng for eight hours on a sand bath under a reflux condenser 

 with 80 grms. of baryta. 



The small quantity of esters of Fraction 3 produced in the second 

 distillation was treated in the same way, and the liquids united. The 

 hquid was allowed to stand for several days to allow the barium salt 

 of racemic aspartic acid to crystallise out. A large amount of baryta 

 crystalhsed out as well. The crystals were filtered off and washed 

 with cold water. They were then placed in a large volume of water, 

 heated up on the water bath, and the baryta removed by means of 

 excess of sulphuric acid. The barium sulphate was filtered off and 

 carefully washed and the excess of sulphuric acid quantitatively removed 

 from the filtrate and washings by baryta. The barium sulphate was 

 again filtered off, washed, and the filtrate and washings evaporated 

 to dryness on the water bath. The residue was slightly coloured, 

 but the colour was easily removed by extraction with 10 c.c. of cold 

 water. 



The crystals were filtered off, washed, dried, and weighed 4-58 grms. 

 equal to a percentage of 



4-58 

 9««^ns ^ ^'■'^^ ^^ aspartic acid in the protein. 



0-1533 grm. gave NHg equal to 11-6 c.c. N/10 acid 



= 0-01624 gram N 



= 10-59 per cent. N. 

 Calculated for C4H7NO4 = 10-53. 



Treatment of the filtrate from the barium aspartate. 

 {Fraction 3.) 



The usual method adopted with the filtrate is to remove the barium 

 quantitatively with sulphuric acid, concentrate the solution in vacuo, 



