£2 Sir H. Davy’s researches on flam#. 
the pressure was the same for the different gases, and-they^ 
were consumed as nearly as possible in the same time, and 
the flame applied to the same point of the copper cup, the 
bottom of which was wiped after each experiment. 
The results were as follows : 
O 
The flame from olefiant gas raised the thermometer to 270 
hydrogene - 238 
sulphuretted hydrogene - - 232 
coal gas - 236 
gaseous oxide of carbon - - 218 
The quantities of oxygene consumed (that absorbed by 
the hydrogene being taken as 1 ) would be, supposing the 
combustion perfect, for the olefiant gas 6, for the sulphuretted 
hydrogene 3, for the carbonic oxide 1. The coal gas con- 
tained only a very small proportion of olefiant gas ; supposing 
it to be pure carburetted hydrogene, it would have consumed 
4 of oxygene. Taking the elevations of temperature, and 
the quantities of oxygene consumed as the data, the ratios of 
the heat produced by the combustion of the different gases, 
would be for hydrogene 2 6, for olefiant gas 9.66, for sulphu- 
retted hydrogene 6.66, for carburetted hydrogene 6, for car- 
bonic oxide 6*. 
It will be useless to reason upon this ratio as exact, for 
charcoal was deposited both from the olefiant gas and coal 
gas during the experiment, and much sulphur was deposited 
from the sulphuretted hydrogene ; and there is great reason 
to believe, that the capacities of fluids for heat increase with 
their temperature. It confirms, however, the general con- 
• These results may be compared with Mr. Dalton’s new System of Chemical 
Philosophy ; they agree in showing that hydrogene produces more heat in combus- 
tion than any of its compounds. 
