COMPOUND UREAS. 231 



fuses at 63 ; and boils without decomposition at 223 ; 

 soluble in water, alcohol, and ether. 



Ureas with bivalent alcohol radicles are also known. 

 In the formation of these, however, two or more mole- 

 cules of urea usually unite. 



i-vrTT (^2TT3(^) 

 -^ H 2 is produced, when 



acetyl chloride is poured upon urea (a spontaneous 

 elevation of temperature takes place, and hydrochloric 

 acid is evolved) ; and by heating urea with acetic anhy- 

 dride. Long, silky needles ; but slightly soluble in 

 cold water, more easily in hot water and alcohol ; fuses 

 at 112, and is decomposed at a higher temperature, 

 forming cyanuric acid and acetamide. Does not com- 

 bine with acids. Bromacetyl-urea, CO.N 2 H 3 (C 2 H 2 BrO), 

 is formed by the action of bromacetyl bromide on 

 urea. Colorless needles, difficultly soluble in cold 

 water, more easily but with decomposition in hot. 

 Tribromacetyl-urea (see Barbituric Acid, p. 239). 



Similar compounds, ureas, in which hydrogen atoms 

 are replaced by acid radicles, are formed by the action 

 of various agents on uric acid. 



Sulphocarbamide (Sulpho-urea), CS(NH 2 ) 2 . Is pro- 

 duced by heating dry ammonium sulphocyanate to 

 170. Long, silky needles, or thick, short rhombic 

 prisms ; fusing point, 149 ; easily soluble in water 

 and alcohol. Heated with water to 140, it is recon- 

 verted into ammonium sulphocyanate. Combines with 

 acids, oxides, and salts, like urea. 



"The hydriodate and hydrochlorate are produced by 

 treating persulphocyanic acid with hydriodic acid, or 

 tin anct hydrochloric acid. 



When its solution is digested with silver, lead, or 

 mercury oxides, it is converted into dicyano-diamide 

 (p. 217). 



Ethyl-sulphocarbamide, CS j ^^ i 8 pro- 



duced by dissolving ethyl mustard-oil (p. 214) in alco- 



