184 THE ROYAL SOCIETY OF CANADA 



become much less than atmospheric. The gasometers are joined to 

 the piping system by means of wire-lined flexible gasoline hose. 



III. The Hydrogen Cycle 



Plate 1 of the previous communication^ plainly shewed the 

 general arrangement of the hydrogen cycle. The installation repre- 

 sented in the above plate has undergone none but minor alterations, 

 except for the gasometer that has been added to the low pressure 

 system already described in Section II of this paper. 



Ordinarily the gas is kept under pressure in steel cylinders tested 

 to 200 atmospheres pressure. From the cylinders it is introduced by 

 means of reducing valves into the gasometer from which it passes to 

 the intake of the compressor. After compression the gas is passed 

 through oil and water separators and then to the purifying or liquefy- 

 ing cycles, from whence it returns again at low pressure to the intake 

 of the compressor. Extreme precautions are taken to prevent the 

 escape or loss of gas in any manner. To this end all valves and unions 

 are immersed wherever possible in heavy oil, that serves to indicate 

 instantaneously a leak and prevents air from contaminating the 

 system during the exhausting of the apparatus. By these means it is 

 possible to run the cycle continuously without introducing more gas 

 into the system than is required to replace that which is condensed 

 as liquid. After each operation the gas is collected and compressed 

 into the steel cylinders where it is safely stored until required. 



IV. The Purification of the Hydrogen 



The commercial hydrogen that we are using may contain, we find, 

 when manufactured electrolytically, as much as 1.5 per cent, oxygen 

 and from 0.1 per cent, to 0.3 per cent, nitrogen. The presence of 

 oxygen may be accounted for by the diffusion that takes place in 

 the porous plates of the electrolytic cell, but the presence of nitrogen 

 is due probably to contamination during the compression or storage. 



In our operations the preliminary purification of the commercial 

 hydrogen is efi^ected by passing it through a high pressure bomb 

 filled with palladiumized asbestos. This bomb is heated electrically 

 to about 350°C. at which temperature the palladium acts as a strong 

 catalyst, and the oxygen and the hydrogen combining to form water 

 is later condensed in a trap or taken up by caustic potash. When 

 the hydrogen at a pressure of 200 atmospheres is passed over this 

 asbestos a number of times the content of oxygen in the hydrogen 

 may be reduced to less than . 1 per cent. 



"McLennan, Trans. Roy. Soc. of Canada, May, 1921. 



