208 Hydrolysis of the Soluble Protein of Sivede Turnips 



filtered off and the excess of sulphuric acid removed by baryta. The 

 clear filtrate was concentrated on the water bath and gave a strong 

 alkaline reaction. Cold aqueous phosphotungstic acid was now added 

 until no further precipitate was obtained. The precipitate was filtered 

 off, the clear filtrate freed from phosphotungstic acid by baryta 

 and excess of baryta removed by sulphuric acid. On concentrating the 

 filtrate a crop of crystals separated out. These were filtered off and 

 weighed 1-03 grms. Upon treatment with animal charcoal and recrystal- 

 hsation 0-1100 grm. of it gave NHg equal to 6-65 c.c. N/10 acid 



= 0-00931 gram N 

 = 8-46 per cent. N. 



It gave the xanthoproteic reaction and also the odour of phenylacet- 

 aldehyde on heating with potassium bichromate and sulphuric acid. 

 Phenylalanine contains 8-49 per cent. N. The substance which had 

 separated out must have been phenylalanine. 



ASPARTIC AND GlUTAMINIC AcIDS. 



The yields of glutaminic and aspartic acids obtained in this hydrolysis 

 were so unusually low that it was considered advisable to find whether 

 better yields could not be obtained by the apphcation of Foreman's 

 method to the hydrolytic Hquid direct. This method has already 

 been referred to in this paper; it was appUed to the filtrate from the 

 insoluble barium aspartate of Fraction 3. 



When this research was in progress the method had not yet been 

 pubhshed and the following determinations were carried out under 

 Mr Foreman's direction and with his kind co-operation. 



Hydrolysis of the protein. 



A weight of protein equal to 32-90 grms, of the dry ash-free substance 

 was hydrolysed by boihng with 120 c.c. of concentrated hydrochloric 

 acid under a reflux condenser for forty-eight hours. The hydrolytic 

 hquid was concentrated under reduced pressure in order to remove 

 most of the hydrochloric acid. 



Treatment with calcium oxide. Preparation of calcium salts. 



The cold residue was diluted with about 200 c.c. of water. 18 grms. 

 of pure hme were placed in a litre flask and slaked with 100 c.c. of 

 distilled water. The hydrolytic liquid was added to this slowly with 

 constant cooling. The flask was then corked and shaken up for thirty 



