OF ARTS AND SCIENCES. 



17 



salt was a mixture of a salt of xanthocobalt with a smaller proportion 

 of the corresponding salt of the octamin series. 



The above results clearly show that the action of alkaline nitrites 

 upon salts of cobalt in presence of free acid is extremely complex, not 

 less than six classes of salts being formed, of which two belong cer- 

 tainly to basic series, while three may be regarded as salts of ammo- 

 nium. The sixth, Co2(NH3)g(N02)g, is probably also one term in a 

 hexamin series. 



8. The ammonia-nitrites discovered by Erdmann are of especial in- 

 terest. They present the first and at present the only known instance 

 in which cobalt, by uniting with ammonia and nitroxyl, NO.,, forms an 

 electro-negative or chlorous radical. The compound Co2(NH,5)^(NO.,)3 

 may be regarded as existing in combination with two atoms of a mon- 

 atomic radical, exactly as the compound Co2(NH3)g(N02)4 combines 

 with two atoms of chlorine. The structural formulas may be written 

 respectively : — 



Co, 



'NH3-NO, 



NHj-NO^ 



NH3-NHI-CI 

 ] NH3-NH3-CI 

 I NH3-NO2 

 [NH3-NO2 



Co, i 



NH3-NO, 

 NH3-NO2 



N<^>N-0-OK 



N<Q>N-0-OK 



NH„-NO, 



NH3-NO; 



"With these formulas we may advantageously compare those of chlo- 

 ride of luteocobalt, of Fischer's salt considered as anhydrous, and of 

 chloride of xanthocobalt : — 



,0, 



rNH3-NH3-Cl 



Co, < 



NH3 



NH3-NH3 



NH3-NH3 



NH,-C1 

 CI 

 CI 



Co, 



N<Q>N-0-OK 



NH, 



-NH3-CI 



NH3-NH3-CI 



N<^>N-0 

 N<Q>N-0-OK 



>N-0-OK 

 OK 



N<0 

 ,0 



N< 



O 



>N-0-OK 

 >N-0-OK 



Co, < 



NH3-NO, 



nh3-nh;-ci 



NHg-NH^-Cl 

 NH3-NH,'-C1 

 NH1-NH,,'-C1 



nhI-no,' 



VOL. X. (N. S. II.) 



