Atomic Volume and Specific Gravity. 53J^ 



number which we assume as unity. But on the supposition 

 that AgO takes the place of HO, the difficulty ceases. 



NH^H, HO, SO3 =44 

 vjdmua « NH^H, AgO, SO3 = 44 + NH^H = 66 

 ,). t„ NHjH, AgO, Cr03= 44 + NH2H = 66 



Perhaps the most anomalous salt in the whole series ex- 

 amined is chloride of ammonium, which actually decreases 

 one volume in becoming solid, 9 x 4 in solution being 11x3 

 in the state of a salt. Chloride of potassium refuses to share 

 this anomaly, and we accordingly find it 9*8 x 4, and NH4CI 

 associates itself to KCl in the double salts. Four volumes for 

 NH4CI is undoubtedly what we should expect from its com- 

 position, and from that number being affected in solution and 

 in its double salts. We also see the three volumes entering 

 into alpha ammonia-chloride of copper, although the beta 

 ammonia-chloride, according to our results, seems singularly 

 enough to affect the proper four volumes. 



NHjH, HC1 = 33 



NHgCu, HCl = 33 -f- NH^H = 22 + HO = 11 = 66 



NHgCu, HCl = 38-4 or 9-8x4 = 39-2 

 The double amides and chlorides, as we have already shown, 

 affect the same number of volumes as NH4CI when in solu- 

 tion, and might be placed on the same type as NHgHg, HCl. 

 Without denying that NH2H and HO may be so intimately 

 associated in the ammoniacal salts as to form the hypothetical 

 body oxide of ammonium, we would call attention to the facts, 

 which show that the resulting volumes of the ammoniacal salts 

 are made up of the volumes of the hydrated acid and amide of 

 hydrogen. It by no means militates against that view, that 

 in hydrated sulphate of ammonia we have one volume in solu- 

 tion less, and also in the state of a solid, than should result 

 from the combination of these two. CuCl has undoubtedly 

 per se two volumes, just as HCl has in a concentrated state, 

 or as NH2H has in combination. But the CuCl in CuCl 

 -I- 2 HO possesses only one volume, the other having disap- 

 peared in the water; and HCl itself has only one volume in 

 dilute solutions. The disappearance of one volume in combi- 

 nation with water is by no means so surprising as the disap- 

 pearance of the volumes of 23 atoms of the constituents of 

 alum in the water in which it is dissolved, especially when we 

 find the salt under consideration, sulphate of ammonia, vindi- 

 cating its proper volume when in combination. The oxalate 

 of ammonia has its proper volume, just as has anhydrous sul- 

 phate of ammonia ; the only exception is the decidedly anoma- 

 lous salt — chloride of ammonium, although this also ceases 



