§3 J- SAKUEAI. 



point of o-]ycGCo]l and its insolubility in alcohol and ether. A similar 

 view of tlie constitution of taurin had already been put forward by 

 Erlenmeyer. 



The great analogy in properties between glycocoll and anhydrous 

 beta'in (triniethyl-glycocoll) on the one hand, and the close relationship 

 between the latter and choline on the other, a relationship which 

 establishes the constitution, 



H,C-N(CH3)3 



I i 

 OC - 



for anhydrous beta'in, giye a further support to the correctness of the 

 closed formula. 



Again, the obseryatif^n made by ^larckw^ald, Xeumark. and 

 Stelzner (7Vr.. 24, 327!) [1.S91]), that glyc.^coll does not readily react 

 with mustard oils to form derivatives of thio-urea, contrary to the 

 behaviour of all primai-y amines, speaks against the commonly adopted 

 open formula for glycocolh 



All other ]>roperties of this compound are in perfect accordance 

 with the constitution of tlie internal ammonium salt, and there is not 

 a single reaction which needs to be expressed by the open formula ; 

 on the contrary, there are several, as will be shown later on, which 

 can not be ex])lain('d by it. 



In spite of the evident claim of the internal ammonium theory 

 to be exclusively adopted, it is astonishing to find th:it there are most 

 eminent authors who do not recognise it frankly and make common 

 use of it, and others Avho eyen disregard it altogether.^'* AYhile insist- 



(1) Beilsteiu [Handhuch : 2 Aufl , I, 1182-1183 [1893]) does not even mention the closed 

 formula. Roscoe and Schorlemmer [Treat iw : 2 Ed., Ill, Ft. 2 [1890]) say in one place (p. 20) 

 tliat glycocoll must be considered as an ammonium salt, but in desci-ibing its reactions they 

 expressly use the open formula (pp. 20 and 100) ; alkyl g-lycocolls are, on the other hand, repre- 

 sented by the closed formula. V. Meyer and Jacobson {Lclirhucli : I, 828 [1893]) seem to be 

 greatly in favour of the internal ammonium theory, but do not use it consistently ; in fact, like 



