326 Dr. T. Andrews on the Heat disengaged during the 



Hence we have for the heat evolved during the combination 

 of— 



One litre carbonic oxide with oxygen . . 3057 

 One litre oxygen with carbonic oxide . . 6114? 

 One gramme oxygen with carbonic oxide 4255 

 One gramme carbonic oxide with oxygen 24-31 

 The mean of Dulong's experiments is 3130 for the combus- 

 tion of one litre of carbonic oxide. 



Marsh Gas and Oxygen, 

 The marsh gas was obtained from a stagnant pool. It con- 

 tained an unusually large proportion of nitrogen. A large 

 excess of oxygen was employed to burn it. 



M 360-2 c.c. 359-0 c.c. 360-0 c.c. 



Mc 359-3 c.c. 358-1 c.c. 359-1 c.c. 



R 105-0 c.c. 108-5 c.c. 125-2 c.c. 



Re 105-8 c.c. 109-4 c.c. 126-1 c.c. 



B 30-10 in. 30-10 in. SO'IO in. 



T 15°-8 15°- 7 14^-1 



E 1°'0 l°-o 1^-0 



I 2°-504 2--457 2^-317 



Ic 2°-509 2°-462 2°-322 



W 268-1 grms. 238-7 grms. 268-7 grms. 



V 28-1 grms. 28*1 grms. 28-1 grms. 



1. 2. 3. 



9413 9431 9420 



We have, therefore, for the heat evolved during the com- 

 bination of — 



One litre marsh gas with oxygen . 94-20 

 One litre oxygen with marsh gas . 4716 

 One gramme oxygen with marsh gas 3277 

 One granmie marsh gas with oxygen 1 3 1 08 



A single experiment with the gas prepared artificially from 

 the acetate of potash, gave 9171 units for the heat produced 

 by the combustion of one litre. The gas however was not free 

 from empyreumatic odour. 



If we apply a similar correction for the heat produced by 

 the condensation of the vapour of water to that employed be- 

 fore in the case of the combustion of hydrogen, we shall obtain 

 for the true lieat due to the combination of one gramme of 

 oxj'gen with marsh gas 2931 units. 



Olcjiant Gas and Oxygen. 

 The olefiant gas, prepared and purified by the usual pro- 

 cesses, was still tbund to c(mtain 6*4 vols, of carbonic oxide 



