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LORD KELVIN, DR. M. MACLEAN, AND MK. A. GALT, ON THE 



51. A conjecture occurred to us that this very surprising result might possibly 

 be due to the formation of lines of conductance from the electrifying needle to the 

 inside of the containing cylinder, so that all the electricity from the needle might be 

 passing to the glass and tinfoil strips without electrifying the intervening air, and 

 that if means were provided for continually breaking these conjectural lines of con- 

 ductance the results would be diffei'ent. Accordingly a hexagonal ring of sheet tin 

 an inch broad was constructed to serve as stirrer. Its outer diameter was slightly 

 less than the diameter of the cylinder. Two rods which passed through two air- 

 tight holes in the metallic top of the glass cylinder were fixed at the ends of a 

 diameter of this stirrer. Several experiments were tried (1) with the stirrer not 

 moved but resting near the surface of the water at the bottom of the cylinder, 

 (2) with the stirrer kept moving up and down during the electrification, which was 

 by needle points at 5000 volts, in each experiment. The results obtained disprove 

 our conjecture. They are summarised as follows : 



ELECTRIFICATION OF CARBONIC ACID GAS FROM PRESSURE CYLINDER. 



52. One of the carbonic acid cylinders of the Scottish and Irish Oxygen Company 

 was taken and laid on its side near the glass cylinder, C (fig. 7). Carbonic acid gas 

 from it was let in by a tube into the glass cylinder, and electrified by six needle 

 points. To start with, the stop-cock of the carbonic acid gas cylinder was kept 

 shut, and ten strokes of the pump caused the water in the cylinder to rise. The 

 stop-cock was then opened and carbonic acid was allowed into the cylinder, the 

 average time of letting it in being one minute. This was performed five or six times, 



