vi THE SALTS OF GLYCOCOLL 215 



that the acid radical of one molecule links on to the basic radical of a 

 second molecule : l 



NH 3 



H 2 C 7 X CO 



OC<" >NH 3 or 



^x. <r f\r\ PTT 



0, J \ / |(U i 



NH 3 . 



Whatever change an amino-acid undergoes, whether it form a 

 ring-like compound on becoming an internal salt, or whether it form 

 double molecules, or whether it become hydrated, or whether it 

 unite with acids, the originally trivalent nitrogen always become 

 pentavalent. 



Glycocoll Hydrochloride, C1H 3 N.CH 2 .COOH, by hydrolysis 

 sets free neutral glycocoll H 2 N.CH 2 .COOH and hydrochloric acid, 

 which then dissociates into the ions H + Cl'. The solution reacts 

 strongly acid, owing to the hydrogen -ions, and it conducts the 

 electric current mostly as hydrochloric acid, and to a very slight 

 extent as the hydrochloride of glycocoll. 



GlyCOCOllate of Sodium, H 2 N.CH 2 .COONa: by hydrolysis 

 neutral glycocoll and sodium hydrate are set free. The latter 

 dissociates electrolytically into OH'- and Na-ions. The solution has a 

 strongly alkaline reaction owing to the hydroxyl-ions, and it conducts 

 the current mostly as sodium hydrate, and to a very slight extent as 

 sodium glycocollate. 



In connection with the union of amino-acids with carbon-dioxide 

 Siegfried 2 has made the following observation, which is of the greatest 

 physiological importance : 



On saturating a mixture consisting of equal volumes of equinormal 

 solutions of glycocoll and barium-hydroxide, an alkaline solution is 

 obtained which remains clear when C0 2 is passed through it, and this 

 continues to be the case till for each volume of glycocoll nearly two 

 volumes of equivalent baryta water has been added. The solution so 

 obtained gives off barium carbonate slowly on standing and quickly 

 on boiling. Analogous results are obtained on substituting for 

 glycocoll i-alanin, 1-leucin, sarcosin, phenyl-glycocoll, aspartic acid, 

 glutaminic acid or asparagin, and on replacing barium-hydroxide by 

 calcium or sodium hydroxide, and finally on substituting for C0 2 

 sodium carbonate. 



Analyses of the compounds which glycocoll, i-alanin, 1-leucin, sarcosin, 



1 The formation of anhydrides or di-acipiperazin rings is explained on pp. 55, 132. 

 2 M. Siegfried jfcifecfcr. /. physiol. Chem. 44. 85 (1905). 



