122 Dr. Kane on the Theoretical Constitution 



\. Cl H 4 N and Cl Cu + Cl H 4 N. 



2. C) Cu N H 3 and Cl Cu 4- Cl Cu H 3 N. 



3. Cl Zn N H 3 and Cl Zn + Cl Zn H 3 N. 



4. Cl Hg N H 3 and Cl Hg + Cl Hg H 3 N. 



The completeness of the analogy thus indicated is acknow- 

 ledged by Graham, who proposes to extend the Berzelian the- 

 ory so as to include these cases. He assumes, that in the 

 compound radical ammonium the hydrogen may be replaced 

 by a metal, and thus a cuprammonium N H 3 Cu, a zincam- 

 monium N H 3 Zn, a hydrargammonium N H 3 Hg, may be 

 capable of individual existence. If Hgand H are replaceable, 

 then Hg 2 H 2 N is equivalent to H 4 N, and thus he agrees with 

 me that the type of sal-ammoniac and white precipitate 

 (Cl H . H Ad and Cl Hg + Hg Ad on my theory) is the same. 



But why have we not Cl Hg 3 H N, or Cl Cu 3 H N, or Cl 

 Hg 4 N and Cl Zn 4 N, taking their place among these bodies 

 generated by ammonia ? For Cu 4 N or Zn 4 N would also be 

 equivalent to ammonium. The replacement stops when there 

 remain yet two equivalents of hydrogen to the nitrogen ; and 

 it is only by a temperature such as destroys completely the 

 constitution of these bodies that a metallic azoturet can be 

 produced. 



The compounds containing oxygen acids are precisely simi- 

 lar to those chlorides just described. The bodies 



SO 3 . OCuNH 3 and S O 3 . O Cu + SO 3 . O Cu NH 3 



S O 3 . O Zn N H 3 and S O 3 . O Zn+ S O 3 , O Zn N H, 



SO 3 .OHNH 3 and SO S .OH +SO 3 .OHNH 3 

 and SO 3 .NH 3 +SO 3 .OHNH 3 



are so obviously similar in constitution, that the one explana- 

 tion of their internal structure must be admitted. 



There exist thus two sorts of compounds, which are ordinary 

 ammoniacal salts with metallic oxide in place of water, or in the 

 words of the theory of Graham, that contain ammonium in 

 which hydrogen is replaced by a metal ; those as Cl. Hg N H 3 , 

 in which one equivalent, and those as Cl . Hg N H 2 Hg, in 

 which two equivalents have been thus replaced. The sub- 

 stitution stopping there shows that N H 2 is fixed, and thus that 

 even if these various sorts of ammonium be admitted, the ami- 

 dogene must be considered as pre-existing in them; and as 



Graham admits my formula for ammonium N H 4 = Ad , 

 so his metallic ammoniums become 



Ad 



H 



Cu' 



Ad 



H 



Zn' 



Ad 



Hg 



H 



Ad 



Hg 

 He 



and so on. 



Under this form the ammonium theory is capable of being 



