98 Mr. Grove on some Electro-Nitrogurets. 



solid state it could be broken, and its fracture was of a very 

 dark gray, or nearly black colour, something resembling that 

 of cast iron which has been exposed for sometime to the air; 

 it had little or no metallic lustre: on thawing it gave out am- 

 monia, hydrogen and nitrogen. 



My next attempt to procure a solid ammoniacal compound 

 of this nature, was, by forming an extremely fusible alloy of 

 mercury, and Newton's fusible metal. I obtained one which 

 was solid at ordinary temperatures, but which fused at 86° 

 Fahrenheit. I made this the cathode of a voltaic battery in 

 a solution of ammonia gently heated ; it remained perfectly 

 unaltered, giving off the gases as a solid electrode would have 

 done. It now occurred to me that by subjecting a solution 

 of one of the salts of ammonia to electrolysis, having at the 

 anode an oxidable metal ; this would be dissolved and revived 

 at the cathode in conjunction with nascent nitrogen and hy- 

 drogen, and thus a permanent compound might be formed ; to 

 effect this it was necessary that the oxide or chloride of the 

 metal should be easy of reduction, soluble in, and not precipita- 

 ble by, ammoniacal salts ; thus lead, iron, and platina offered 

 little hope of success, and on trial proved ineffectual. Tin was 

 also inefficient from the quantity of insoluble peroxide and 

 oxychloride formed ; with this metal indeed a small quantity of 

 dark-gray spongy matter collected at the cathode, but was 

 soon reacted upon by the solution. With zinc, copper and 

 cadmium, however, the results were very different; and the 

 compounds formed and methods of forming them, I will 

 describe separately. A long glass trough was filled with 

 distilled water, into which were placed several lumps of mu- 

 riate of ammonia; a platina wire forming the cathode, and a 

 button of distilled zinc suspended by a platina wire, the 

 anode of six pairs of zinc and platina plates (charged, as 

 originally proposed by me (Phil. Mag. for May 1839), with 

 dilute sulphuric and concentrated nitric acid,) were immer- 

 sed in the liquid at the two extremities of the trough, and 

 separated by a fence of crystals of the salt. A spongy mass, 

 which appeared to be formed of a cluster of folia or irregular 

 facets, of the colour and lustre of plumbago, soon formed 

 around the cathode, and as it increased in size rose up and 

 floated ; this specific levity was, however, principally due to 

 the gas entangled in its interstices, as when slightly com- 

 pressed between two strips of glass it instantly sank; having 

 formed a sufficient quantity of this sponge it was gently re- 

 moved, placed on a filter, and well washed with distilled 

 water, then dried over a sand-bath at a gentle heat, during 

 which it gave out no ammoniacal odour ; then pulverized by 



