44 



Proceedings of the Royal Irish Academy. 



thev are theoretically impossible if its constitution is truly represented 



c = c\ 



by tbe foiTaula | / XH. 



C = c/ 

 H H 



As Tvill be seen, I haye not obtained them; and this fact, I think, 

 lends to confirm the theory of Baeyer. I haye experimented with the 

 mucates of diethyl and diamyl-amine. 



DistiUatian of Diethjlammonium 2Iucate. 



This salt is obtained by dissolying mucic acid in solution of diethyl- 

 amine, eyaporating and crystallizing. It contains water, and is 

 extremely soluble both in that liquid and in alcohol. When heated 

 in the paraffin bath it decomposed with intumescence and eyolution of 

 carbonic anhydride, like the primary salt, but at a somewhat lower 

 temperature. The distillate, as before, was a watery solution of 

 (liethylammonium carbonate, on the surface of which floated a small 

 (Quantity of an oily liquid, possessing the odom-, boiling point, and 

 other characters of ethyl-pyrrol. This was eyidently due to the pre- 

 sence of some primary amine in the diethylamine used.' 



The retort residue was a black, carbonaceous mass, burning with 

 fiame. fi-om which neither by solvents nor by fui'ther heating could 

 anything suitable for analysis be extracted. 



• Distillation of Diaraylamraonium JHucate. 



Easily formed by the dii-ect union of diamylamine* and mucic 

 acid. The resulting compound is freely soluble in water and 

 alcohol. The distillation, which was slowly conducted oyer the naked 

 flame, in every respect resembled that of the preceding salt. Owing 



' Tlie diethylamine ■tt-as prepared from diethyloxamic ether, hoiling -nithiii a 

 few degTees of 264' C. As ohtained in the sepai-ation of the ammonia bases by 

 oxalic ether, it is impossible (at least on the small scale) to separate it from simnl- 

 taneously-fonned monoethyloxamic ether CWallach). Hence the presence of 

 ethylia in the diethylia extracted from it by caustic potash. Baerer (" Berichte," 

 vii. 963) has now shown that by the action of caustic soda on nitroso-diethyl- 

 aniline and nitroso-dimethyl-aniliiie, dimethylamine and diethylamine may be 

 obtained in a state of absolute purity. But as this method, the only really satis- 

 factory one, is somewhat costly, I propose to separate the primary and secondary 

 bases by the distillation of their- mucates. If the quantity of primary base be 

 small, the secondary base ^^ill alone be liberated in the free state. I am not, how- 

 ever, prepared ^^ith analytical proofs. 



s Diamylamine is usually stated, on the authority of its discoverer, Hofmanu, 

 to boil at 170' C. I have found, however, that it (that is, the variety prepared 

 fi-om ordinaiy amylic alcohol) boils at 1S5'-1S7'. That which I employed in these 

 experiments boiled within a few degTees of this temperature, and 3-et evidently con- 

 tained much amylaminc (B.P. 95- C.). I am convinced that the complete separa- 

 tion of the primary, secondary, and teitiaiy amylamines by fractional distillation is 

 .as little feasible as that of the ethyl bases by the same process. 



