140 Analyiei of Books. [Auo* 



xnents to decide it. Indeed no difference whatever is to be 

 found between the specific gravities of any gases either simple 

 or compound in the author's present work, and those contained 

 in the last edition of his System, except in five cases of the latter. 



The recent experimental researches detailed are not founded 

 upon more obvious or easy principles, but with the increased 

 difficulty of complexity. Of this the last method employed 

 to ascertain the atomic weight of ammoniacal and azotic 

 gases offers an abundant proof. After having determined the 

 atomic weight of azotic gas by the analysis of atmospheric air, 

 nitric acid, protoxide and deutoxide of azote and nitrous acid, 

 and having proved its weight to be 1*75, and having arrived at the 

 same conclusion from the analysis of ammonia, the Doctor offers 

 what he allows to be " a redundancy of evidence," as to the 

 composition of ammonia, and consequently the atomic weight 

 of azote. We shall give this as a fair specimen of very complex 

 analysis, executed, we think, with great skill, and as offering 

 confirmatory evidence of the facts which the operations are 

 intended to illustrate. 



" 1 . Oxalate of ammonia is a neutral salt, which crystallizes 

 in beautiful transparent prisms. It is not very soluble in water. 

 Its constituents 1 have found, by a careful analysis, to be 



1 atom oxalic acid 4*5 



1 atom ammonia 2*125 



2 atoms water , 2*25 



8-875 



8*875 grains of this salt were dissolved in a small quantity of 

 distilled water. 6*25 grains of pure calcareous spar (equivalent 

 to 3*5 graiuvS of lime) were dissolved in muriatic acid : the solu- 

 tion was evaporated to dryness, and the dry residual salt, consti- 

 tuting muriate of lime, was redissolved in a little water. The 

 two solutions being mixed, a double decomposition took place, 

 and oxalate of lime subsided to the bottom. As soon as the 

 supernatant liquid had become quite clear, it was tested by 

 oxalate of ammonia, and by muriate of lime ; but was not rett* 

 dered muddy by either of these reagents, — showing that it con- 

 taijied no lime nor oxalic acid. From this it is obvious, that 

 $•{$75 grains of oxalate of ammonia contain just the quantity of 

 oxalic ajcid requisite to saturate 3-5 grains of lime. Now, 3*5 

 being the atomic weight of lime, the oxalic acid in 8-87.3 gi-ain^ 

 of the oxalate must be the equivalent of an atftm, ov 4v3 ; f oj i^ 

 will bie shown afterwards thui 4-.^4$t4h0iJ|t0aii«! weight of oxalic 

 ^^.ui^:)i:^ ■[: ' ', -w: ' -- • -'- '■ •■ old 



^jy^fb^r {liquid froin which; the oxalate of lime had precipitafclii 

 WB^ neutral ; hence the muriatip acid in the muriate of lime wqs 

 jiut'Capable of saturating thewhole amoioniaia.the 8'875 graii»» 



