Dr. Hofmann on the Separation of the Ethyle-Bases. 477 



the composition of which was determined by the analysis of the 

 platinum-salt and gold-salt. 



Platinum-salt. — Needles, difficultly soluble in boiling water, 

 soluble in concentrated hydrochloric acid, from which well-formed 

 crystals are deposited, containing 



C 8 H 22 As N Pt 2 Cl = [(C 2 H 4 )" < C » H ^ 3 3 n]" C1 *> 2 pt cl a- 



Gold-salt.— Yellow compound precipitated from the dichloride 

 obtained in the previous platinum-determination, on addition of tri- 

 chloride of gold, soluble in hydrochloric acid, deposited from this 

 solution in golden-yellow plates of the composition 



C 8 H 22 As N Au 2 Cl 8 = [(C 2 HJ" (C 2 H 5 ) 3 H s As N]" Cl 2 , 2 Au Cl 3 . 



I have also made a few experiments on the action of dibromide of 

 ethylene upon trietbylstibine. The reaction is slow, and requires 

 long-continued digestion at temperatures higher than that of boiling 

 water. The tubes invariably contained much gas ; and the product 

 of the reaction proved to be a complex mixture of several compounds, 

 many of them secondary, which in no way invited me to a more 

 minute examination of this process. I omit to quote the few pla- 

 tinum- and chlorine-determinations which were made, since they do 

 not admit of a simple interpretation. 



" Contributions towards the History of the Monamines." — No. IV. 

 Separation of the Ethyle-Bases. By A. W. Hofmann, LL.D., F.R.S. 

 The preparation of the ethyle-bases by the action of ammonia upon 

 iodide of ethyle, presents a difficulty which greatly interferes with 

 the general application of this otherwise so convenient method. This 

 difficulty consists in the simultaneous formation of all the four ethyle- 

 bases. The equations 



H,N+C a H,I=:[(C a H 3 ) H 3 N]I* 

 (0, H 5 ) II 2 N + C. H 3 1= [(C H 5 )„ H N j I 



(c;h 8 ) s h n+c;h,i=[(c;h 8 );h n] i 



(c.h.), n + c 2 h 5 i=[(c 2 h 5 ) 4 n]i, 



are an ideal representation of the four different phases through which 

 ammonia passes during its transformation into iodide of tetrethyl- 

 ammonium. In practice it is found impossible to carry out this 

 transformation in the several steps indicated by these equations. 

 The first substitution-product, generated as it is in the presence of 

 the agent of substitution, is immediately acted upon again, the second 

 product being formed, which in its turn may be converted into the 

 third and even into the fourth compound. The following equations 

 represent perhaps more correctly the final result of the several 

 changes which are accomplished in the reaction of ammonia on 

 iodide of ethyle. 



H 3 N + C H 3 1 = [(C, IL ) H 3 N] I" 

 2ILN + 2 CCH-I=[(C,H-),H N] 1+ [II, N] I 

 3 II 3 N + 3 CI H 5 I = [((X H 5 ) 3 II" N] 1+2 ([II ( NJ I). 

 4H 3 N+4C:iI 6 I=[(C 2 H 5 X N] 1 + 3 ([II, N] I). 



* 11 = 1; 0=16; C = 12,&c. 



