114 HEINRICH ROSE ON THE COMBINATIONS OF 



were effected in such manner that only the most volatile sublimate 

 of each operation was employed for the following subhmation : 

 0-619 grm. of the obtained product gave 1-441 gi-m. of metallic 

 platina, and from 0-552 grm. 1-288 grm. of carbonate of barytes 

 were obtained by the chloride of barium ; the liquid filtered from 

 it gave, with ammonia, 0-068 grm. more. This corresponds to 

 40-48 per cent, ammonia, and 52-30 per cent, carbonic acid ; and 

 the last precipitate obtained 2-76 per cent, carbonic acid. The 

 salt then does not become anhydrous by frequent sublimation. 



If we admit that the composition first obtained is the con-ect 

 one, and that the other salts contained a slight mixture of a 

 combination, Avith a larger proportion of carbonic acid, then in 

 fact this composition must appear a very remarkable one, for it 

 is not favourable to the ingenious hypothesis proposed by Berze- 

 lius, that ammonia is changed into the oxide of ammonium by the 

 reception of 1 atom of water, and is thus converted into a base. 

 I shall, however, subsequently endeavour to show that the neu- 

 tral anhydrous carbonate of ammonia has great tendency to 

 form double salts, especially with the bicai'bonate of the oxide 

 of ammonium. This tendency it appears to evince also towards 

 the simple carbonate of the oxide of ammonium, which does not 

 seem to exist independently in a solid state. The most probable 

 view which we may therefore take of the composition of the 

 neutral hydrous carbonate of ammonia is, that we should look 

 upon it as a combination of the carbonate of ammonia with the 

 carbonate of the oxide of ammonium, (C + NH^) + (C NH* ). 



If the anhydrous neutral salt, obtained by the mixture of the 

 two gases, is not well preserved and protected from moisture, it 

 appears to change into the hydrous neutral combination. On 

 analysing such a salt, which had been sublimed, I obtained 

 from 1-259 grm., 2-929 grm. of metallic platina, and from 0-784 

 grm. 1-844 of carbonate of baiytes. This answers to 40-46 per 

 cent, ammonia, and 52-72 per cent, carbonic acid. 



It is surprising that the formation of the neutral carbonate of 

 ammonia, during the distillation of the common sesquicarbonate, 

 or a mixture of sal-ammoniac and dry carbonate of soda, has 

 escaped the attention of chemists. I must, however, remark, 

 that John Davy mentions in his paper* that his brother had 

 obtained, on exposing the sesquicarbonate to heat, a salt which 



* Edinburgh New Philosophical Journal, vol. xvi. p. 257. 



