79

a few experiments on the comparison of thepowers of hydrogene, in this respect, withthose of carburetted hydrogene, azote, oxy-gene, olefiant gas, nitrous oxide, chlorine,and carbonic acid gas. The same ther-mometer raised to the same temperature,160°, was exposed to equal volumes (21cubic inches) of olefiant gas, coal gas, car-bonic acid gas, chlorine, nitrous oxide gas,hydrogene, oxygene, azote, and air, at equaltemperatures. 52° Fahrenheit.

The times required for cooling to 106*were for

Air -

1 n

2

Hydrogene

45

Olefiant gas

1.15

Coal gas

55

Azote -

1.30

Oxygene

1.47

^Nitrous oxide

2.30 2.53

* Carbonic acid gas -

2.45

Chlorine

3.6

It appears from these experiments, that

* These two last results were observed by Mr.Faraday of the Royal Institution, when I was absentfrom the Laboratory.