HYDROGEN AND NITROGEN. 413 



lent in several of the sulphates, and with a whole equivalent in 

 several of the chlorides of the magnesian family. 



Ammoniated salts, closely related to the preceding, are often 

 obtained on transmitting ammoniacal gas through a strong solu- 

 tion of such salts as, in the dry state, combine with ammonia. 

 Nitrate of silver crystallizes with two atoms of ammonia (G. 

 Mitscherlich) ; nitrate of copper, with two also, and no water 

 (Kane) ; sulphate of copper, with two ammonia and one water ; 

 chlorides of copper and zinc, with the same (Kane). 



AMMONIUM. 

 Eg. 226.96 or 18.19; N H 4 or H 2 Ad; not isolable. 



A compound radical consisting of ammonia with an additional 

 atom of hydrogen, was first supposed to exist in the ordinary 

 salts of ammonia by Berzelius, and termed ammonium. This 

 body has never been insulated, but is supposed to appear, in a 

 certain experiment, in combination with mercury, and possessed 

 of the metallic character (page JJ6). It is not necessary, how- 

 ever, that ammonium be a metal to be admitted as a basyle, 

 and its existence is now generally rested upon evidence of a 

 different nature. The compounds of ammonium are always 

 strictly isomorphous with the corresponding compounds of po- 

 tassium. 



Chloride of ammonium, hydro chlorate or muriate of ammonia, 

 sal ammoniac, N H 4 , Cl. This salt is formed when ammonia 

 is neutralized by hydrochloric acid ; N H 3 and H Cl = N H 4 , Cl. 

 It is prepared in large quantity from the ammoniacal liquor 

 obtained in the distillation of bones, in the manufacture of 

 animal charcoal, and from the liquor which condenses in the 

 distillation of coal for gas. These liquors contain ammonia 

 principally in the state of carbonate and hydrosulphuret, which 

 may be converted into chloride of ammonium by the addition 

 of hydrochloric acid. The salt is purified by crystallization, and 

 sublimed in vessels of iron or earthenware, in the upper part of 

 which it condenses and forms a solid cake, the condition in 

 which sal ammoniac is always met with in commerce. 



Sal ammoniac is tenacious and difficult to reduce to powder ; 

 its sp. gr. is 1.45. It has a sharp and acrid taste, and dissolves 

 in 2.72 parts of cold, and in an equal weight of boiling water ; it 



