and Salts in Muriate and Nitrate of Ammonia, 99 



riate of ammonia, a yellowish brown- coloured precipitate en- 

 sues. The nitrate of ammonia acts much in the same way 

 as the muriate. 



Salts of Cadmium.— \, The oxide and carbonate dissolve 

 in a cold solution of muriate of ammonia. 



2. The phosphate and oxalate also dissolve in tlie cold fluid. 



'6. The prussiate does not undergo solution. 



The nitrate of ammonia is a less perfect solvent of the salts 

 of cadmium than the muriate. 



Salts of Platinum.-^\, The triple compound, chloride of 

 platinum and potassium, is soluble in muriate of ammonia, as 

 is also the chloride of platinum and ammonia. 



None of the sulphurets of the preceding metals undergo so- 

 Jution in muriate or nitrate of ammonia. In all the experi- 

 ments the ammoniacal salts were added to the recently preci- 

 pitated oxides and salts. The solution of phosphate of lime 

 in muriate of ammonia may, hov^'ever, be nearly if not entirely 

 precipitated by an excess of caustic ammonia: if, on the con- 

 trary-, only a small quantity of the caustic alkali be added, 

 although a slight precipitate v^'ill take place and the fluid be 

 slightly alkaline, still when filtered it will be found to contain 

 lime by the addition of oxalate of ammonia. In the analysis, 

 therefore, of a solution in muriatic acid supposed to contain 

 phosphate and carbonate of lime, if sufficient ammonia be not 

 added over and above that which is necessary to render the 

 fluid somewhat alkaline, the filtered solution will be precipi- 

 tated by oxalate of ammonia, and might lead to the supposition 

 that carbonate of lime was present: if even an excess of ammo- 

 nia had been employed and the fluid heated, the same source of 

 fallacy would exist, because the excess of ammonia would have 

 been driven off, and the resulting fluid would contain phos- 

 phate of lime in solution; the same applies to the phosphate 

 of baryta and strontia, also to the phosphate of magnesia. 



The salts of lead which are soluble in muriate of ammonia, 

 are precipitated from that solution by an excess of caustic am- 

 monia : hence in precipitating solutions of lead by sulphuric 

 or oxalic acid, where an ammoniacal salt exists, care should be 

 taken that the fluid be strongly alkaline, so as to counteract 

 the solvent power of the ammoniacal salt; the presence of 

 lead in such solutions would, however, be readily detected by 

 sulphuretted hydrogen or hydro-sulphuret of ammonia. The 

 fact of the oxides of iron not being soluble in muriate of am- 

 monia might afford a means of separating them from several 

 other metallic oxides with which they are frequently united, 

 more particularly the peroxide: by this means the latter might 

 be separated from lead, mercury, antimonv, zinc, bibniuth^ 



02 



