424 



I moreover showed how this equation applies to the first terms of the 

 series of diammonium- as well as triammonium-salts. 



In following up the natural development of these ideas, I had to 

 search for the tetrammonium-compounds. For if w=3, the above 

 equation reduces itself to 



3R Br a + 6 H, N= [R 8 H 10 NJ" Br 4 + 2([H 4 N]Br) ; 



and the simplest tetramine of the ethylene-series the triethylene- 

 tetramine is represented by the formula 



I have vainly searched for this compound among the difficultly vola- 

 tile bases resulting from the action of dibromide of ethylene upon 

 ammonia, which distil after the triammonias have passed. But it is 

 obvious that so complex a compound must have a very high boiling- 

 point, and thus be liable to decomposition by distillation. To avoid 

 this decomposition, the product of the action of dibromide of ethy- 

 lene upon ammonia was treated with an excess of oxide of silver ; the 

 liberated bases were then submitted to a long-continued current of 

 steam, by which all the volatile matter was carried over. A consi- 

 derable proportion of non-volatile bases remained behind, the mixed 

 character of which was easily proved by progressive precipitation by 

 dichloride of platinum. The analysis of these platinum-salts has con- 

 vinced me that this liquid indeed contains the tetramine in question, 

 mixed, however, with other compounds of very similar properties ; so 

 that my endeavours to obtain it in a state of purity have failed. I 

 have, however, succeeded in preparing the pure compound by a some- 

 what different process, viz. by submitting ethylene-diamine, instead of 

 ammonia, to the action of dibromide of ethylene. The formation of 

 the tetrammonium-compound in this reaction is represented by the 

 equation 



The hydrobromic acid which figures in this equation arises from an- 

 other phase of the reaction, which I have not yet completely studied. 

 Triethylene-tetramine is a powerfully alkaline liquid which is sepa- 

 rated from the bromide by means of oxide of silver. It dries up to 

 a syrup, which shows no tendency to crystallize. Its composition 



