on the Nature of certain Bodies. 457 
tained .8 of ammonia, 11 of the residuum, detonated with 8 of 
oxygene, left 8. 
The second portion equalled 2 cubical inches. They con- 
tained no ammonia. 10 of this gas, with 8 of oxygene deto- 
nated, left a residuum of 10. 
There remained in the tube and adaptors 1.1 cubical inch 
of gas. 
The quantity of hydrogene produced by the action of the 
potassium, which had been regenerated, equalled 4.5 cubical 
inches. 
In this experiment the heat was applied much more slowly 
than in any of those in which the iron tube was used, and even 
at the end of the operation, the temperature was little more 
than that of cherry red. 
In the upper part of the stop-cock there was found a minute 
quantity of gray powder, which gave ammonia by the opera- 
tion of moisture. 
In no case, in which I have used the copper tube in like 
processes of slow distillation, has there been less than“4 grains 
of potassium revived ; and the proportion of nitrogene to the 
hydrogene in the gas evolved has been uniformly much 
greater than in processes of rapid distillation in the tubes of 
iron ; but the whole quantity of elastic matter procured con- 
siderably less. 
Copper has a much stronger affinity for potassium * than 
* Copper heated in potassium speedily dissolves, and diminishes its fusibility ; but 
potassium requires' a white heat to enable it to combine with iron. In another expe- 
riment, in which I distilled the fusible substance in an iron tray, contained in the 
copper tube, a considerable quantity of copper, that had been dissolved, was found 
in the state of powder deposited upon the tray, or loose in the bottom of the 
tube. 
