68 M. C. Lea on Triethylamine. 



the picrates of ethylamine and triethylamine crystallize out in 

 yellow needles. The separation of these last from each other by 

 crystallization when the triethylamine is present in considerable 

 proportion, cannot be as satisfactorily effected, as when it is pres- 

 ent in small quantity only. It therefore became necessary to 

 seek for a good mode of effecting this separation. 



Triethylamine is but moderately soluble in water, and when 

 the water present is insufficient to dissolve it, it forms a layer on 

 the surface. It seemed possible that its affinity for ether might 

 be greater than for water, and experiment proved this to be the 

 case. When ether is agitated with aqueous solution of ammonia, 

 ethylamine, or diethyla'mine, it takes up but little of the base, 

 but when agitated with aqueous solution of triethylamine, it be- j 

 comes strongly charged. A portion of ether agitated with a mix- 

 ture of the aqueous solutions of ethylamine and triethylamine 

 and then treated with hydrochloric acid and bichlorid of platinum \ 

 and spontaneously evaporated, gave only crystals of triethylam- i 

 ine salt, which is easily distinguished from the platinum salt ot 

 ethylamine : no traces of the presence of the latter were observa- 

 ble. It therefore seemed worth while to test the process by a care- 

 ful series of analvses, which was done with the following results. 



The moderately strong aqueous solution of the mixed bases, 

 triethylamine and ethylamine, was agitated several times with 

 about -rV its bulk of ether and left some time to separate thor- 

 ough! v, after which the ether was removed by a separating fun- 

 nel. This was repeated three or four times. It was evident that 

 if these ethereal solutions of triethylamine thus obtained were 

 contaminated with ethylamine, the latter substance would be 



f resent in largest proportion in the latter portions of the ether. 

 a order therefore to render the test more rigorous, these latter 

 were examined in preference, and with the following results. 



Portions of the etherial solution were treated with excess of 

 hydrochloric acid and converted into platinum salt with excess 

 of bichlorid of platinum. 



(1.) '7031 gras. substance gave metallic platinum, "'"'f 



These correspond to 



u 



Mean of two analvses, - - - 32-13 

 Theory requires (Pt=98-7)*- - 32-13 



An eminently satisfactory result. 



In order to ascertain if the whole of the triethylamine were 

 removed by this proceeding, the aqueous solution, after four 

 washings with ether, was submitted to analysis. Its chloroplati- 

 nate gave by ignition 



* T have taken this number for Ft as that adopted by the last numbers of th^ 



