Carbonic Acid and Ammonia. 255 



after having been washed with a little distilled water, to remove 

 any adhering scsquicarbonate. The crystals were transparent 

 and inodorous, and some of them were nearly half an inch in 

 diameter. 



That No. 4 and 5 was in small prismatic crystals, and was 

 also washed with distilled water, and dried in the atmosphere. 



That No. 6 and 7 was in powder, procured by exposure of 



the sesquicarbonate for two or three weeks to the atmosphere, 



till it had lost its ammoniacal odour. h 



And that No. 8 and 9 was in powder, obtained by digesting 



the sesquicarbonate in alcohol. 



Calculating on the maximum quantity of carbonic acid gas 

 disengaged from one grain of the salt, viz. 1.18 cubic inch, and 

 on the mean quantity obtained from five grains, namely, 8.6 

 grains, on the data before given, this salt would appear to be 

 composed of 



21.56 Ammonia, 

 56.01 Carbonic Acid, 

 22.43 Water ; 

 or of 



17 Ammonia, - (1 proportion 17.) 

 44.1 Carbonic Acid - (2 proportions 44.) 

 17.66 Water - (2 18.) 



an approximation even greater than might be expected. In rela- 

 tion to the quantity of carbonic acid, it seemed preferable, in 

 the instance of the sesquicarbonate, to take the maximum for- 

 forming the estimate ; and in that of the bicarbonate the maxi- 

 mum, as the tendency of the former salt is to pass into the neu- 

 tral ; and of the latter salt to retain a little of the sesquicarbon- 

 ate, and probably to generate it. 



Considering the methods of analysis employed, I am disposed 

 to think that the slight differences in the results, in the several 

 instances, arise, not so much from imperfection in the experi- 

 ments, as from slight difference of composition in the salts them- 

 selves, which, if I do not deceive myself, will readily be admit- 

 ted, after the statement of some particulars, which I shall now 

 proceed to give concerning the bicarbonate. 



This salt is less soluble in water than the sesquicarbonate, 

 and more readily deprived of a portion of its carbonic acid, by 



82 



