the Hot Gases from Flames. 41 



The following table shows the result of an experiment : — 





Velocity of 

 the carrier. 



Temp. 



Conductivity 



of the gas 



proportional 



to 



Distance of 



the terminal 



from the 



flame. 



At terminal A 



At terminal B 



At terminal C 



cm. 



"23 per sec. 



•21 „ 

 •04 „ 



°0. 

 230 



160 



105 



26 

 3 

 1 



cm. 

 55 



10 



14-5 



Evidently for some distance from the flame the velocity of 

 the carrier was very little altered, and then began to rapidly 

 diminish. This diminution of velocity seems to depend prin- 

 cipally on the cooling of the gas, and would point to a rapid 

 condensation on the charged carrier of some uncharged body 

 greatly increasing its mass. 



To test whether a similar falling away of the velocity would 

 occur in the case of a flame which burns without the production 

 of water-vapour, a CO flame was tried ; and a similar dimi- 

 nution of velocity was found. 



The velocity of the carrier in the CO flame was found to be 



•16 cm. per second, 



under an electric force of 1 volt per cm., and at a distance of 

 30 cm. from the flame, where the temperature was 55°, this 

 velocity had fallen to 



*03 cm. per second. 



Some other experiments are in progress to investigate more 

 fully this falling away of the velocity of the carrier. 



6. Discharging Power of Fine Gauze. 



When the velocity of the carrier under an electric force has 

 diminished at a distance from the flame, it can pass through 

 gauze without being discharged much easier than if the gauze 

 is placed closer to the flame. 



In one experiment a charged terminal placed in the tube, at 

 a distance of about 35 cm. from the flame, leaked at the rate of 

 50 scale-divisions in 30 sec. One layer of fine gauze placed 

 in the tube just below this terminal, and therefore at a point 

 where the velocity of the carrier was small, scarcely diminished 

 the rate of leak. The same gauze when placed 10 cm. from 

 the flame reduced the leak from the same terminal to 50 divi- 

 sions in 75 seconds. 



