250 BACTERIAL POISONS. 



tliat lictaiue has properly the composition CgHi-jNOj, which 

 is expressed by the structural formula : 



N(CH3)30H 



I 

 OH, 



COJI. 



The free base is, however, readily converted into the 

 anhydride, CjHuNOj, trimethyl glycocoll ; the structural 

 formula of which is : 



CH-N(CH3)3 

 CO— o. 



Betaine is ordinarily regarded as crystallizing with one 

 molecule of water, and the composition is expressed by the 

 formula: C^Hj^NO^ + Hp (= OH.N(CH3)3.CIl2.C02H). 

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

 on standing over sulphuric acid, forming an anhydride of 

 the formula already given. Lij:breich claims that free 

 betaine possesses the formula CjHjjNOj, because it yields a 

 compound having the composition (C5HjjN02)ZnCl2. The 

 free base separates from alcohol in large crystals which deli- 

 quesce on exposure to the air. As obtained by Beibgee 

 from the hydrochloride by treatment with moist silver 

 oxide, it possessed a sweetish taste and neutral reaction. 

 AVhen distilled with potassium hydrate, it yields trimethyl- 

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

 CjITjyNOg occurs in the largest quantity. 



The Chloeide, C5H12NO2.CI, 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 

 (IjIPPMANn). 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 



