Thialdine and Selenaldine. A'j'j 



tained. We M^iU here merely aUude to an explanation of the 

 constitution ^d basic character of thialdine, at once obvious, 

 namely, that it may be regarded as a copulated compound of 

 sulphide of ammonium with 3 eqs. of a body 



C4 H3 S, 

 which is the sulphide corresponding to the oxide in aldehyde, 

 namely, sulphide of acetyl. ^ ' 



2. Selenaldine. 

 ^ The existence of thialdine and the mode in which this base 

 IS tormed, induced us to try the preparation of a correspond- 

 n! ^!}TT^ compound. We perfectly succeeded in obtain- 

 ing that body : selenaldine, however, is so soon and easily 

 altered, that we have not as yet been able to subject it to a 

 more profound investigation. 



.nlnf!r^^?Tir'rP'°'l'''''^ bypassing into a concentrated 

 solution of aldehydite of ammonia hydroselenic acid gas, dis- 

 engaged from selenide of iron by means of sulphuric acid, 

 in order to prevent the decomposition of hydroselenic acid 

 Wn fin^'Y^^" °^ ^}^ atmosphere, the whole apparatus had 

 been filled previously with hydrogen. The excess of the poi- 

 sonous hydroselenic acid was condensed in a potassa appa- 

 ratus. After some time the solution of aldehydite of ammonia 

 Degins to become turbid, and crystals of selenaldine are de- 

 posited. When the mass of crystals is no longer augmented, 

 the excess of hydroselenic acid is expelled by a stream of hy- 

 drogen gas; the solution of selenide of ammonium, covering 

 the crystals, which soon turns red and deposits selenium, i1 

 now displaced by introducing a stream of cold water, free from 



wr?K T.?/'' *^'r^^ °"" «^ ^^^ g^^^« tubes connected 

 with the bo tie. The crystals are then collected upon a 



sulThuric'add '^^*'" ^""^^^ °^ bibulous paper and dried over 

 Selenaldine, as it is deposited from the liquid in which it 

 forms, presents itself in small colourless crystals, doubtless 

 isomorphous with thialdine. In contact with the atmosphere 

 It turns immediately yellow. This substance has a feeble but 

 disagreeable odour; it is slightly soluble in water, on which 

 account it should not be washed too long. The aqueous so- 

 lution and the last washings become soon turbid in contact 

 with the atmosphere, and dc])osit an orange-yellow body. 

 1 he same deportment is exhibited by the solution of sclc- 

 naldnie in alcohol and aether, in both of which it is easily 

 solubJe. In consequence of its being so easily altered, we 

 did not succeed in obtaining this base in crystals from any of 

 the solutions mentioned. On evaporating them ia vacuo over 



