130 HEINRICH ROSE ON THE COMBINATIONS OF 



0*643 grm. of the salt prepared in this manner, and obtained on 

 another occasion, gave with muriatic acid 182*25 cub. centim. of 

 carbonic acid gas, which answers to 5G*11 per cent, of carbonic 

 acid in the salt. 



The bicarbonate is likewise formed when, instead of the hydrate 

 of potash and the quick lime, chloride of calcium is employed, 

 and a saturated solution of the sesquicarbonate is evaporated 

 with it in vacuo. 0*632 grm. of the salt obtained, treated with 

 muriatic acid, gave 179*67 cub. centim. of carbonic acid gas, 

 which corresponds to 56*28 per cent, of carbonic acid in the salt. 

 The chloride of calcium did not smell of ammonia after the ex- 

 periment, but it had taken up carbonate of ammonia, and, when, 

 dissolved, deposited carbonate of hme, whilst the muriate of 

 ammonia was dissolved. If the crystals of the |- carbonate of 

 ammonia (of which I shall speak in one of the following sec- 

 tions) are dissolved in water, and the solution is evaporated 

 over sulphuric acid in vacuo, incrustations of the bicarbonate 

 are obtained. 0*638 grm. gave 180*576 cub. centim. of carbonic 

 acid gas, or 56*03 per cent, of carbonic acid. 



In works on chemistry it is stated, that if the common ses- 

 quicarbonate be kept for a long time in vessels, in which it is 

 not perfectly protected from the action of the air, it is gradually 

 converted into bicarbonate. This statement is perfectly accu- 

 rate. The more volatile carbonate flies off gradually, and the 

 less volatile bicarbonate is left behind. I powdered some of 

 the common sesqmcarbonate, and kept it for five months in a 

 dry room, in a vessel covered over with paper, which had been 

 pricked with a needle. The powder was shaken from time to 

 time. 2*021 grm. of the powder gave 2*510 grm. of metallic pla- 

 tina, and 0*728 grm., treated with muriatic acid, 205*5 cub. 

 centim. of carbonic acid gas. This corresponds to 



Ammonia 21*60 



Carbonic acid 55*88 



Water 22*52 



100-00 



The composition of the bicarbonate of the oxide of ammonium, 

 as well as that of the bicarbonate of potash, is quite analogous to 

 that of the bisulphate of potash, and of the bisulphate of oxide of ' 

 ammonium. These may, as is well known, be regarded as double 

 salts of the sulphate of potash, or of oxide of ammonium, with hy- 



