194 Hydrolijsis of the Soluble Protein of Swede Turnips 



(ii) Treatment of the residue in the distillation flask. 



This was shaken up with water and ether to extract any phenyl 

 alanine ester. The aqueous extract was saponified by boiling with 

 baryta, the barium removed with sulphuric acid, and the filtrate added 

 to the hquid for making lead salts. 



(iii) Treatment of residue insoluble in ether (soluble in chloro- 

 form). 



This was boiled Avith water under a reflux condenser for seven hours, 

 acidified with sulphuric acid (up to 5 per cent.) and treated with 25 per 

 cent, phosphotungstic acid to remove the bases. The sulphuric and 

 phosphotungstic acids were removed from the filtrate by means of 

 baryta and the liquid added to the others for preparing lead salts. 



Preparation of lead salts from filtrates (i), (ii), and (iii). 



The lead salts were made just as described before, only the treatment 

 with lead hydroxide was discarded. The acidity disappeared almost 

 completely so that much lead chloride was produced. The dry lead 

 salts weighed 271 grms. The undissolved htharge weighed 525 grms. 

 and contained 1-54 grms. of nitrogen. The liberation of the esters 

 from the hydrochlorides by baryta in chloroform solution was carried 

 out quite easily, no addition of water being found necessary. 



The baryta residue used weighed 740 grms. and contained 11-7 grms. 

 of nitrogen. The residue of esters left after distilling off the chloroform 

 was completely dissolved by dry ether. The ether was distilled off as 

 completely 'as possible at the ordinary pressure and the esters fraction- 

 ally distilled as before. 



Fractional distillation of the second yield of esters. 



The liquid air condenser contained 35 grms. of liquid, mainly ether 

 and chloroform. 



The undistilled residue weighed 16-3 grms. 



Fraction 1. 



The esters were immediately reconverted into their amino-acids 

 by boiling under a reflux condenser with four times their volume of 

 water. The alkaline reaction, however, did not disappear, even after 

 heating for fourteen hours. The chloroform was distilled off at the end of 



