423 



solution on cooling in large rectangular tables presenting the aspect 

 of nitrate of silver. The combustion of this salt has led to the 

 formula 



Trinitrate C 



LH^K.b.ifkfX Uj 



H. I 



The formation of the diethylated diethylenetriamine is readily 

 intelligible. I have satisfied myself that the origin of this body was 

 always due to the presence of minute quantities of ammonia which 

 had not been entirely removed from the ethylamine employed in the 

 reaction. 



r(C 2 H 5 )] 1 H] r(C 2 H 4 ) 2 V .-i* 



3TT I AT I TT I "\T I O f/r* TT \ii "R-n 1 (C^ TT \ I N" "Rr 



L \ JN +-H. V JN + ^ L(^2 -"-4) -" r 2 J == (^2-^5)^ f ^3 ** T * 



H j Hj H 8 J 



The formation of diethylene-diethyltriamine furnishes an elegant 

 illustration of the simple mechanism involved in the construction of 

 the polyatomic bases. 



VII. "Notes of Researches on the Poly- Ammonias." No. XVIII. 

 Tetrammonium-Compounds. By A. W. HOFMANN, LL.D., 

 F.R.S. Received July 29, 1861. 



In several previous communications I have submitted to the Royal 

 Society a sketch of the triatomic bases which are generated by the 

 assimilation of three molecules of ammonia linked together by the 

 intervention of diatomic molecules. In the same sketch I endea- 

 voured to trace the general principle upon which the bases of higher 

 atomicity are formed. I pointed out that the accumulation of am- 

 monia-molecules is determined by the number of diatomic radicals 

 which are fixed; that, for the production of an (w-f i)-atomic am- 

 monia, at least n diatomic radicals are required ; and lastly, that 

 the number of molecules of diatomic bromides and the quantity of 

 ammonia involved in these accumulative processes are given in the 

 general equation 



W R U Br 2 +2rc H 3 N= [R." H (2n+4) 



