1893-94.] S. Kimura on Electrical Properties of Gases. 
203 
On Certain Electrical Properties of Iron Occluding Gases. 
By S. Kimura, RigakusM. (With Two Plates.) 
(Read December 18, 1893.) 
I. The Driving-off of the Occluded Gases by Heating. 
Since the occlusion of hydrogen and carbonic oxide by palladium 
and iron was first discovered by Graham, many similar effects have 
been discovered. Prof. Knott* has investigated in considerable 
detail the very peculiar changes in the thermo-electric position and 
in the electrical resistance of palladium when variously charged 
with hydrogen. With respect to iron. Dr Monckmanf has ex- 
perimented on the resistance of iron occluding carbonic oxide, but, 
in regard to hydrogen, he came to the conclusion that no change 
in the thermo-electric properties could be detected. 
My object in making the following experiments was at first to 
investigate the thermo-electric properties of iron occluding various 
gases, and, on pursuing the experiments, I observed in the course 
of heating a very peculiar change, substantially the same as was 
observed by Prof. Knott on hydrogenium. The iron used in these 
experiments was a sample of commercial wire, and its thermo- 
electric power was numerically indefinite; but, besides this, the 
thermo-electric change itself was smaller than in the case of two 
severed halves of the same specimen of wire, which had been 
annealed with different degrees of care. I therefore changed the 
subject of investigation, and thereafter paid exclusive attention to 
the escape of the occluded gases. 
First, I took an iron wire occluding carbonic oxide, and obtained 
a fairly good result. Then the existence of carbonic acid in meteoric 
iron suggested me to try this gas also. In this experiment I obtained 
a result equally well defined with that observed in the case of 
carbonic oxide. Lastly, I tried iron occluding hydrogen. As to 
* Proc. Roy. Soc. Eclin., 1882-83 ; Trans. Roy. Soc. Eclin., 1886. 
t Proc. Roy. Soc. Lond., 1888. 
