AMMONIA WITH CARBONIC ACID. 113 



quantity of water necessary to convert the ammonia into the 

 oxide of ammonium is present. A composition calculated ac- 

 cording to the chemical formula C + NH^ + ^ H, gives in the 

 hundred, 



Carbonic acid 50*52 



Ammonia 39*20 



Water 10-28 



100-00 



On repeating the experiment I obtained from 1-420 grm., 

 3-288 grm. of platina, and from 0*390 grm., 0-837 grm. of cai'- 

 bonate of barytes ; and after an addition of ammonia, also 

 0-059 grm. This answers to the following composition : 



Carbonic acid 51*49 



Ammonia 40*26 



Water 8*25 



100*00 

 It sometimes happens that it is difficult to obtain the salt per- 

 fectly pure. That its solution is not entirely precipitated by a 

 solution of chloride of barium, but that, after the precipitation, 

 a slight precipitate is still produced by ammonia, is almost al- 

 ways the case even with the solution of the anhydrous neutral 

 salt. 



The hydrous neutral carbonate of ammonia can, without 

 changing very essentially in its composition, be again sublimed. 

 1*552 grm. of the twice sublimed salt gave, treated in the man- 

 ner above mentioned, 3*692 grm. of metallic platina; and 0*446 

 grm. by means of chloride of barium, 1*009 grm. of carbonate of 

 barytes ; a precipitate of 0*077 grm. was nevertheless produced 

 by ammonia. This answers to 41*37 per cent, ammonia, 50*71 

 per cent, carbonic acid, and also 3*87 per cent, carbonic acid in the 

 precipitate caused by ammonia. We see clearly, that this salt, 

 by the double sublimation, had changed in a small degree into a 

 combination containing more carbonic acid, though it remained 

 doubtful whether this was in consequence of the renewed action 

 of heat, or on account of the attraction of moisture. 



I then subUmed the first sublimate which had been obtained 

 from two pounds of the sesquicarbonate,not less thanfive times, in 

 order to see whether, by this means, it might entirely lose its water, 

 and change into an anhydrous salt. The renewed sublimations 



VOL. II. PART V. H 



