244 ACTION OF POTASSIUM ON AMMONIA. 



ignited iron upon potash, in the happy method discovered 



by M. M. Gay Lussac and Thenard, rinding that it gave the 



same results, and could be obtained of a Uniform quality*, 



and infinitely larger quantities, and with much less labour 



and expense. 



Potassium When ammonia is brought into contact with about twice 



brought m:o . , t „ . 



contact with lts weight ot potassium at common temperatures, the mrtal 



ammonia. loses its lustre and becomes white, there is a slight diminu- 

 tion in the volume of the gas ; but no other effects are pro- 

 duced. The white crust examined proves to be potash, and 

 the ammonia is found to contain a small quantity of hidro- 

 gen, usually not more than equal in volume to the metal. 

 Heated in the Q n heating the potassium in the gas, by means of a spirit 

 lamp applied to the bottom of the retort, the colour of 

 the crust is seen to change from white to a bright azure, 

 and this gradually passes through shades of bright blue and 

 green into dark olive. The crust and the metal then fuse 

 together ; there is a considerable effervescence, and the 

 crust, passing off to the sides, suffers the brilliant surface of 

 Cooled. . the potassium to appear. When the potassium is cooled in 

 this state it is again covered with the white crust. By heat- 

 Heated a se- ing a second time, it swejls considerably, becomes porous, 

 time * and appears crystallized, and of a beautiful azure tint; the 

 same series of phenomena, as those before described, oc- 

 cur in a continuation of the process ; and it is finally 

 entirely converted into the dark olive coloured substance. 

 Hi'.rogen? In this operation, as has been staled by M. M. Gay Lus- 



?L,J«!o-\ ?r! sac an d Thenard, a gas, which ffives the same diminution bv 

 ammonia (lis- 7 © » » 



appears. detonation with oxigen as hidrogen, is evolved, and ammo- 



nia disappears. 



The proportion of the ammonia, which looses its elastic 



The potassium * When the potash used for procuring potassium in this operation 

 probablv con- , , . • ,-, . , i 



taminat d was rer ^ I )Ure » anc ' tne iron turmn gs likewise very pure and clean, and 



with a little * ne "whole apparatus free from any foreign matters, the metal produced 

 iron. differed very little, in its properties, from that obtained by the Voltaic 



battery. Its lustre, ductility, and inflammability w?ro similar. Its 

 point of fusion and specific gravity were, however, a little higher, it re- 

 quiring nearly 150° of Fahrenheit to render it perfectly fluid, and being 

 to water as 7960 to 10000, at 00° Fahrenheit. This lam inclined to at- 

 tribute to its containing a minute proportion of iron; 



form, 



