124 THE ROYAL SOCIETY OF CANADA 



it goes to shew that the residual ionisation observed in the gases 

 tested with the exception of acetylene was probably due to a radiation 

 emitted by the zinc walls of the electrometer which was partly of the 

 alpha, partly of the beta and possibly partly of the gamma type 

 with roughly about 37% of the ionisation due to alpha rays. 



Considering the case of acetylene we see that in the second in- 

 vestigation as in the first an exceedingly high value was obtained for 

 both the natural and the residual ionisation in this gas. From Table 

 III it will be seen that under alpha and beta rays it was ionised to about 

 the same extent as ethylene, and as the residual ionisation in ethylene 

 was 6-32 ions per c.c. per second while in acetylene it was 27 ions 

 per c.c. per second, it is clear that the high residual ionisation in the 

 latter gas cannot be accounted for by an alpha and beta radiation 

 from the walls of the electrometer. 



It would look rather as if the ionisation in this case was either 

 really spontaneous or else that it was due to some chemical action set 

 up in the electrometer owing to the presence of some gaseous impurity. 



To test the latter hypothesis an experiment was made with hydro- 

 gen prepared by adding water to commercial calcium hydride. The 

 manner in which the hydrogen is produced in this case is very similar 

 to that in which acetylene is obtained from calcium carbide, and it 

 was though that if a gaseous impurity were present in the acetylene 

 the same impurity might be expected to be present in the hydrogen 

 as well. The natural ionisation in the laboratory in hydrogen pre- 

 pared in this manner however was 1 • 8 ions per c.c. per second which is 

 very close to 1-96 ions per c.c. per second the value found with hydro- 

 gen prepared by the action of sulphuric acid on zinc. It would seem 

 therefore that in acetylene we have an ionisation where the atoms or 

 molecules of the gas are being broken up into portions oppositely 

 charged and that this process goes on naturally without the assistance 

 of an agency such as alpha, beta or gamma rays. It should be added 

 that although the argument presented in this paper, precludes the pos- 

 sibility of the residual ionisation in air being due to collisions between 

 moleculer in thermal agitation, it does not exclude this agency in the 

 case of acetylene. The ionisation in acetylene may then be due 

 either to molecular collisions or a to spontaneous breaking up of the 

 atoms or molecules of the gas, but to decide between these two addi- 

 tional experiments will have to be made. 



I. Summary of results. 



(1) From experiments made on the ice on Lake Ontario 

 it would appear that the residual ionisation observed in air, 

 carbon dioxide, hydrogen, nitrous oxide, and ethylene is not 



