112 HEINRICH ROSE ON THE COMBINATIONS OF 



of ammonia with the quantity of water which exactly suffices to 

 change the ammonia into the oxide of ammonium. 



I was much surprised at obtaining a hydrous neutral carbo- 

 nate of ammonia in an unexpected manner. For if the scsqui- 

 carbonate of ammonia of commerce is exposed in a retort to a 

 very gentle heat, and if the neck of the retort is connected with 

 a longish glass tube, the other end of which is immersed in mer- 

 cury, a disengagement of pure carbonic acid gas is first perceived, 

 and in that part of the glass tube furthest from the heated retort a 

 crystalline salt is deposited, the solution of which, in water, is so 

 entirely precipitated by a solution of the chloride of barium, or 

 the chloride of calcium, that ammonia produces no opacity, or 

 at least only a very slight one, in the liquid separated from the 

 carbonate of the earth. This salt is the most volatile of the solid 

 products, which are produced during the distillation of the ses- 

 quicarbonate ; if a gentle heat is applied for some time to the 

 retort, the salt melts, and other combinations are formed and 

 sublimed, which will subsequently come under our notice. 



If the sesquicarbonate is exposed to a stronger heat, but little 

 of the neutral salt is produced. It is therefore necessary to ap- 

 ply a very gentle heat, and only to emploj' for examination the 

 products which are deposited in the part furthest from the heated 

 portion of the retort. When this is not carefully attended to, a 

 mixture of other combinations is obtained. 



A mixture of sal-ammoniac and carbonate of soda gives, when 

 exposed to heat under similar circumstances, the same salt. With 

 this distillation, at first only ammoniacal gas escapes, as will be 

 subsequently shown. 



1"609 grm. of the sublimate, treated after having been dis- 

 solved with the chloride of barium, gave 3*596 grm. of carbonate 

 of barytes : and 0"860 grm. of the sublimate, prepared in the 

 same way, gave, when treated in the manner above mentioned, 

 with alcohol, aether, muriatic acid, and chloride of platina, 

 1-942 grm. of metallic platina. This corresponds to the fol- 

 lowing composition : 



Carbonic acid 50*09 



Ammonia 39-27 



Water 10-64 



100-00 

 The composition of this salt is very remarkable ; only half the 



