414 COMPOUNDS OF HYDROGEN. 



is also soluble in alcohol. It generally crystallizes from solution 

 in feathery crystals, which are formed of rows of minute octo- 

 hedrons attached by their extremities. 



A corresponding bromide, iodide and fluoride of ammonium 

 may be formed by neutralizing ammonia with hydrobromic, 

 hydriodic and hydrofluoric acids. 



Sulphurets of ammonium. When 4 volumes of ammonia 

 combine with 2 of sulphuretted hydrogen, the sulphuret of 

 ammonium is produced ; N H 3 and H S = N H 4 , S. Ammo- 

 nium combines with sulphur in several other proportions, which 

 are obtained on mixing and distilling the various degrees of 

 sulphuration of potassium with sal ammoniac. In the reciprocal 

 decomposition which occurs, the potassium combines simply 

 with chlorine, and the ammonium with sulphur. The following 

 compounds are generally enumerated : N H 4 , S ; N H 4 , S H- H S ; 

 N H 4 , S 3 and N H 4 , S 5 . The protosulphuret has long been 

 formed by distilling a mixture of quicklime, sulphur and sal 

 ammoniac, and known under the name of the fuming liquor of 

 Boyle. It is a volatile liquid, the vapour of which is decom- 

 posed by oxygen, and thus fumes produced. The second 

 compound, which is a hydrosulphuret of the sulphuret of am- 

 monium, is formed by transmitting sulphuretted hydrogen 

 through solution of ammonia to saturation. This liquid is 

 generally called the hydrosulphuret of ammonia, and is the form 

 in which sulphuretted hydrogen is most frequently used as a 

 reagent. All the sulphurets of ammonium are soluble in water 

 and alcohol without decomposition. 



Nitrate of ammonium, N H 4 O, N O 5 . When nitric acid is 

 saturated with ammonia, a salt is obtained which crystallizes in 

 six-sided prisms, and is isomorphous with nitrate of potash. 

 Besides the elements of nitric acid and ammonia, this salt con- 

 tains an atom of water which cannot be separated from it, which 

 is also found in, and is equally essential to the salts formed by 

 neutralizing all other oxygen acids by ammonia, such as sulphu- 

 rous acid, sulphuric, carbonic, &c., in contact with water. The 

 hydrogen of this water is assigned to the ammonia, to form 

 ammonium, which the oxygen converts into oxide of ammo- 

 nium ; so that the product is nitrate of the oxide of ammo- 

 nium ; or N H 3 and H O, N O 5 = N H 4 O, N O 5 . This salt 

 deflagrates with flame, when thrown upon red hot coals. When 

 decomposed between 3 and 400,, it is resolved into water and 

 nitrous oxide (page 283). 



