$2 Mr. Davy's 'Experiments on 
were found to be absorbed, and 2.48 of hydrogene only 
generated. The distillation was performed, the adaptors 
and tube being full of common air : 8 cubical inches of gas 
were produced ; and there must have remained in the tubes 
and adaptors, the same quantity of residual air, as in the pro- 
cess last described. 
The 8 cubical inches of gas contained scarcely J of a cubi- 
cal inch of ammonia ; and the unabsorbable part detonated 
with oxygene, in the proportion of 1 1 to 6, gave a residuum 
of 7 .5. — The barometer was at 30.2'”-, thermometer at 52* 
Fahrenheit. Dr. Pearson, Mr. Allen, and Mr. Pepys were 
present during the whole of these operations, and kindly 
assisted in the progress of them. 
Now 6.78 — .4 of ammonia =6.38, and this quantity of gas 
decomposed by electricity, would afford 11.4 of permanent 
gas, consisting of 2.9 nitrogene, and 8.5 hydrogene; but 
there are produced in this experiment, of hydrogene, 2.48 in 
the first operation, and 4.28 in the second, and considering the 
nitrogene in the permanent gas as 3.32, .8 must be subtracted 
for the common air; which would give 2. 52 for the nitrogene 
generated ; and to these must be added, the quantity of 
hydrogene and nitrogene in the tubes and adaptors. 
The quantity of potassium regenerated, was sufficient to 
produce 2.9 cubical inches of hydrogene. 
In all experiments of this kind, a considerable quantity of 
black matter separated, during the time the potassium in the 
tube was made to act upon water. 
This substance was examined. It was in the state of a fine 
powder. It had the lustre of plumbago, it was a conductor of 
electricity. When it was heated, it took fire at a temperature 
