Pressure — Afi //imetres of Jffercury 
HYDROGEN AND OXYGEN IN CONTACT WITH HOT SURFACES. 
45 
of steam formation was nearly proportional to the partial pressure of the hydrogen 
throughout. 
Diagram IV. Experiments with silver foil. Pressure curves for normal electrolytic gas. 
Curve A, surface in “normal” condition. Curve C, surface “dehydrogenised ” by oxygen. 
„ B, surface “ hydrogenised ” at 400°. ,, D, surface “ hydrogenised ” at 650°. 
Part IV.— Experiments with Gold Gauze. 
In order that a series of experiments might be carried out with a gold surface 
under as nearly as possible the same conditions as the preceding experiments with 
silver, Messrs. Johnson, Matthey & Co. very kindly prepared a gauze of* fine gold 
wire containing 22 strands (each (PI5 millim. diameter) per centimetre. A rectangular 
piece of this gauze, measuring 23'3 by 9'25 centims., and weighing 52‘9 grammes, 
was employed for the experiments. The surface exposed to the reacting gases would 
he approximately 447 sep centims. 
