250 BACTERIAL POTSOXS. 



that bctaine lias properly the composition ( ',.1 1,. { N r ( ). { , which 

 is expressed by the structural formula : 



N(CH 3 ) 3 <>II 

 CII 2 



CO 2 II. 



The free base is, however, readily converted into the 

 anhydride, C 5 H,,NO 2 , tri methyl glycocoll ; the structural 

 formula of which is : 



CH 2 -N(CII 3 ) 3 



CO O. 



Betaine is ordinarily regarded as crystallizing with one 

 molecule of water, and the composition is expressed by the 

 formula: C 5 H U NO 2 +H 2 O (= OH.N(CII 3 ) 3 .CII 2 .CO 2 H). 

 It loses this water of crystallization by heating at 100, or 

 on standing over sulphuric acid, forming an anhydride of 

 the formula already given. LIKBRKICH claims that free 

 betaine possesses the formula C 5 H n NO 2 , because it yields a 

 compound having the composition (C 5 H u NO 2 )ZnCl 2 . The 

 free base separates from alcohol in large crystals which deli- 

 quesce on exposure to the air. As obtained by BBIEGEB 

 from the hydrochloride by treatment with moist silver 

 oxide, it possessed a sweetish taste and neutral reaction. 

 When distilled with potassium hydrate, it yields trimethyl- 

 amine and other bases, among which a base of the formula 

 C 8 II, 7 N0 5 occurs in the largest quantity. 



The CHLORIDE, C 5 H 12 NO 2 .C1, forms beautiful crystals, 

 monoclinic plates, which are permanent in the air, and this 

 can be made use of to effect a separation from the choline 

 salt, which is deliquescent. It is insoluble in absolute 

 alcohol. This fact can be made use of in their separation 

 (LIPPMANN). It can, moreover, be easily separated from 

 other bases by its aurochloride, which is easily soluble. If 

 a little potassio-mercuric iodide is added to a solution of 

 the chloride, there forms a light-yellow or whitish oily 



