§241. ESTIMATION. 



245 



Triethylamine is not attacked by ethylic oxalate, and can be 

 separated from diethyloxamide and ethylic diethyloxamate by 

 distillation (B.P. 91°). 



The three corresponding methyl bases behave in an exactly 

 similar manner. Trimethylam'me boils at 4° to 5° and can easily be 

 separated from the crystalline methylethyloxamide and the liquid 

 ethylic dimethyloxamate (B.P. 240° to 250°) by distillation. 



§ 241. Estimation. — Sachsse and Kormann ^ have published a 

 method for the approximate estimation of amides, based upon their 

 decomposition by nitrous acid with liberation of nitrogen ; the 



Fig. 10. 



latter gas is collected and measured, and from it the amount of 

 amide originally present is calculated. 



The apparatus used for the estimation is shoivn in Figs. 10 and 11. 

 The generating vessel A is of about 50 to 60 cc. capacity, and 

 closed with an indiarubber cork bored with three holes ; through 

 these there pass two funnel-tubes, a and h, and a bent delivery 

 tube c, to which is attached, by means of a long indiarubber tube, 



1 Landwirthsch. Versuchsst. xvii. 321 (Joum. Chem. Soc. xxvii. 784) ; 

 Zeitschr. f. anal. Chem. xiv. 380, 1875. 



