269 



Ethylene-urea combines with dichloride of platinum and trichlo- 

 ride of gold. 



The platinum-compound is obtained in short prisms of orange-red 

 colour, containing 



C 4 H 10 N 4 2 , HC1, PtCl 2 . 



The gold-salt crystallizes in golden-yellow scales of the composi- 

 tion 



C 4 H 10 N 4 2 , HC1, AuCl 3 . 



The analysis of these compounds fixes the molecular value of the 

 new urea. It deserves to be noticed, that this body, although de- 

 rived from four molecules of ammonia, exhibits nevertheless in its 

 combining power the character of but one molecule of ammonia ; it 

 is a monacid tetramine. 



Diethylated Ethylene-ureas. 



When cyanate of silver is treated with dibromide of ethylene- 

 diethyl-diammonium, a reaction perfectly analogous to that observed 

 between cyanate of silver and dichloride of ethylene-diammonium is 

 accomplished. The solution, when separated from the bromide of 

 silver and evaporated, solidifies on cooling to a crystalline mass. The 

 new substance may be easily purified by dissolving it in absolute 

 alcohol, from which it is deposited in the form of colourless needles, 

 exceedingly soluble both in water and alcohol. The diethylated urea 

 contains 



(C0) 2 " 

 C H NO - ( C 2 H *) 



C 8 il 18 ^ 4 U 2 - ^H^ 

 H 4 



This urea fuses at 1 24, decomposing, however, partially at this 

 temperature. 



It forms a platinum-salt, 



C 8 H 18 N 4 2 , HC1, PtCl 2 , 

 and a gold-salt of very little stability, which could not be analysed. 



Cyanate of ethyl acts most energetically on ethylene-diamine. If 

 the cyanate be poured into ethylene-diamine, each drop hisses like 

 red-hot iron plunged into water. The mixture solidifies into a mass 

 of needles, which, when recrystallized from water or spirit, furnish the 



VOL. xi. u 



