382 [Jan. 8, 



without difficulty in separating the dimethylamine from the mixture 

 of ammonias which this reaction produces. An alcoholic solution of 

 ammonia, gently heated with iodide of methyl in a flask provided 

 with a condenser, rapidly solidifies into a crystalline mixture of the 

 iodides of ammonium, methyl-, dimethyl-, trimethyl-, and tetra- 

 methylammonium. The more soluble iodides separated from the 

 difficultly soluble iodide of tetramethylammonium are evaporated 

 and distilled with potash, and the bases evolved carefully dried by pass- 

 ing over hydrate of potassium, and conveyed through a powerfully re- 

 frigerated serpentine in which dimethylamine and trimethylamine, 

 together with a portion of methylamine, are condensed, the ammonia 

 and the remainder of the methylamine being carried off as gas and 

 condensed in water. The mixture of the three methylated bases is then 

 brought in contact with oxalate of ethyl, when the methylamine imme- 

 diately solidifies into a crystalline mass of dimethyloxamide, 



(C 2 2 )" 



C 4 H 8 N 2 2 =(CH 3 ) 2 N 2 , 



the dimethylamine being converted into dimethyloxamate of ethyl, 



a liquid boiling between 250 and 260, while the trimethylamine 

 remaining unchanged may be expelled from the mixture by gently 

 heating in the water-bath. Dimethyloxamate of ethyl being easily 

 soluble in water, is separated from the dimethyloxamide by treatment 

 of the mixture with cold water. Distilled with hydrate of potash, 

 dimethyloxamate of ethyl yields a mixture of alcohol and dimethyl- 

 amine, oxalate of potassium remaining behind. Evaporated with 

 hydrochloric acid, the distillate furnishes a crystallized residue of 

 chloride of dimethylammonium, from which, on addition of an alkali, 

 the pure dimethylamine is liberated. 



Dimethylamine is a powerfully alkaline liquid of a strongly ammo- 

 niacal odour, easily soluble in water, and possessing the general cha- 

 racters of this class of compounds. Its boiling-point, strange to say, 

 very nearly coincides with that of trimethylamine, the boiling-point 

 of the former being between 8 and 9, that of the latter 9. To 

 eliminate the influence of changes of pressure, the boiling-points of 

 the two substances were determined at the same time. 



