AMMONIA WITH CARBOXIC ACID. 129 



bonate of potash, containing 1 atom of water (2 C + K + H), as 

 1 atom of the oxide of ammonium (NH'') answers to an atom of 

 potash ; but the form also of the crystals of the bicarbonate of 

 ammonia obtained is identical with those of the bicarbonate of 

 potash. The crystals of the latter are, according to Levy*, a 

 right oblique-angled prism of 103° 41', and the crystals of the bi- 

 carbonate of ammonia have the same form. 



I have prepared the same salt in another manner, but then 

 in a pulverulent state. 



If a perfectly saturated solution of the sesquicarbonate is eva- 

 porated over sulphuric acid under an air-pump, and the space 

 over the solution kept as free from air as possible by pumping, 

 it soon boils and deposits a salt difficult of solution. If it be 

 taken out of the solution before it evaporates, and quickly dried 

 between blotting paper, it appears, when analyzed, to be the 

 bicarbonate of ammonia. 1*361 grm. gave 1*662 grm. of metallic 

 platina; and 1*1135 grm., with a solution of chloride of barium 

 and ammonia, 2*753 grm. of carbonate of barytes. This corre- 

 sponds to the following composition : 



Ammonia 21*24 



Carbonic acid 55*42 



Water 23*34 



100*00 

 If a saturated solution of the sesquicarbonate be slowly eva- 

 porated over sulphuric acid in vacuo, and if care be taken not to 

 make it boil by too frequent pumping, another salt is obtained 

 with more carbonic acid than in the bicarbonate, of which we 

 shall speak in one of the following sections. If, however, in- 

 stead of sulphuric acid, hydrate of potash and quick lime are 

 employed for absorbing the water, a crystalline mass is obtained, 

 which is the bicarbonate of ammonia. 1*168 grm. of it gave 

 1*418 grm. of metallic platina, and 0*959 grm,, with a solution of 

 chloride of barium and ammonia, 2*394 grm. of carbonate of ba- 

 rytes. This con*esponds to the following composition : 



Ammonia 21*12 



Carbonic acid 55*95 



Water 22*93 



100*00 



* Quarterly Journal of Science, vol. xv. p. 286. 

 VOL. 11. PART V. I 



