1825.1 -Or ThomsorCs First Principles of Chemistry. 141 



of oxalate of ammonia. Now, this muriatic acid weighed 

 exactly 4*625 grains. And it will be shown in the next para- 

 graph, that 4*625 grains of muriatic acid just saturate 2*125 

 grains of ammonia. This, therefore, is the quantity of ammonia 

 in 8*875 grains of oxalate of ammonia. 



"We have thus determined the weight of acid and ammonia 

 in 8*875 grains of oxalate of ammonia. The surplus weight 

 being undoubtedly water, it is obvious that the constituents of 

 oxalate of ammonia are 



1 atom oxalic acid 4*5 



1 atom ammonia 2*125 



2 atoms water 2*25 



8-875 



The atomic weight of ammonia in this salt is undoubtedly 2*125. 

 " 2. Sal-ammoniac, when newly sublimed, or when dried for 

 some time upon the sand bath, is an anhydrous salt. It is neu- 

 tral ; and, therefore, a compound of one atom muriatic acid and 

 one atom ammonia. 



1 atom muriatic acid 4*625 



1 atom ammonia 2*125 



6*75 



6*75 grains of pure dry sal-ammoniac were dissolved in water ; 

 21*5 grains of pure anhydrous nitrate of silver were dissolved in 

 another portion of water, and the two solutions were mixed. A 

 double decomposition took place, and chloride of silver precipi- 

 tated. As soon as the residual liquid had become clear, it was 

 tested by nitrate of silver and common salt. Neither of these 

 salts produced any effect, if we except an almost imperceptible 

 opalescence which appeared when the common salt was added ; 

 but there was no precipitate whatever, even after the liquid had 

 stood a week. From this experiment it is obvious, that 6*75 

 grains of sal-ammoniac contain just 4*625 grains of muriatic acid ; 

 for that is the quantity necessary to saturate the 14*75 grains of 

 oxide of silver present in 21*5 grains of nitrate of silver. Hence 

 the other constituent of the salt, the ammonia, must weigh 

 2*125, because that is the weight wanting to make up the full 

 quantity of sal-ammoniac employed ; and, as sal-ammoniac is 

 neutral, and 4*625 the atomic weight of muriatic acid, 2*125 

 must be the atomic weight of ammonia. 



" 3. 13*5 grains of dry sal-ammoniac were wrapped up in 

 blotting paper, and dropped into a retort filled with dichloride 

 of hme (Mr. Tennant's bleaching powder), made into a thin paste 

 with water. The whole retort and beak was then filled with 

 wateri and the be^k pf the retort was plunged into a wator 



