The Acid Sulphate of Hydroxylamine. 

 Edward Divers, IVl, D., F. R. S. Prof. 



Imperial University. 



It its .somewhat reirmrkable that although several hydrochhjrides 

 of hydroxylamine ha\e })eeD described by Lo.ssen. the acid .sulphate 

 .seems never to have been obtained. 



It is well known that if more .sulphuric acid is }>re.sent in an 

 aqueous solution of hydroxylamine tlian is suthcient to constitute the 

 normal salt, the addition of alcohol will cause this and not the acid 

 .salt to crystallise out, just as when added to acid ammonium sulphate 

 it will precipitate the normal sulphate. Without this addition of 

 alcohol, a too-acid .solution of hydroxylamine sulphate often refuses to 

 deposit anything. By attention, however, to a tew details, it can be 

 brouoht to yield crystals of the acid sulphate. 



Solid hydroxylamine hydrochloride is to be tre;ited with, as near 

 as may be. the quantity of sulphuric acid calculated to form the acid 

 salt, (NH3Ü)HS0^. Ihc mixing is effected in a disli sufficiently large 

 to avoid loss by frothing over, and this is heated for some houi-s <jn 

 the water bath until all hydrochloric acid has been expelled. The re- 

 sulting clear solution becomes viscid when cold. It refuses to yield 

 the normal sulphate when a particle of this salt is dropped on its 

 surface, and slowdy dissolves it. But left to stand uncovered in a drv 

 cold atmosphere, and the vessel occasionally moved about, crystallisa- 

 tion suddenly sets in and the solution becomes traversed bv long})risms 



