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LIV.— NOTE ON SELENO-CAEBAMIDE. By PEOFESSOE 

 EMEESON EEYNOLDS, M.D., F.E.S. 



[Eead, January 19, 1885.] 



The subject of the present "Note " is the selenium analogue of a 

 body whose isolation I had the honour to announce to the Eoyal 

 Dublin Society in 1869, namely, thio-carbamide. The following 

 formulae indicate the relations of thio- and seleno-carbamides : — 



THIO-CARBAMIDE. SELENO-CARBAMIDE. 



The method by which I succeeded in producing the sulphur 

 compound was the intra-molecular rearrangement by ammonium 

 throughout. But the same body can be obtained by the action 

 of hydrogen sulphide on cyanamide, thus : — 



H3S + CN-NH,= 0S{™1 



The close analogy existing between sulphur and selenium led 

 us to expect that seleno- carbamide would be obtained by methods 

 similar to those which have proved successful in the case of the 

 sulphur compound. I was aware that several chemists unsuccess- 

 fully attempted to produce the body by the molecular rearrangement 

 of ammonium seleno-cyanate ; and, having recently prepared con- 

 siderable quantities of cyanamide, I decided to try whether the 

 second method would prove more successful, namely, the action 

 of hydrogen selenide on cyanamide. The experiment, which 

 proved successful, was conducted as follows : — 



Four grams of cyanamide were dissolved in 50 ccs, of anhydrous 

 ether, and a slow current of hydrogen-selenide was passed through 

 the solution under a pressure of about 60 mms. of mercury. The 

 gas was slowly absorbed, and at first some selenium separated 



SCIEN. PROC. R.D.S. VOL. IV. PT. VIII. 2 P 



