1897.] Newly Prepared Gases. 363 



A similar result was obtained in the case of charged oxygen 

 carrying a cloud ; the corresponding numbers of divisions of the 

 scale being 4 and 20, showed that five times the charge is 

 removed by the tube when it is turned from the vertical to the 

 horizontal position. 



Rough values for the size of the drop might be deduced from 

 these numbers ; but the variations in density per c.c. (due to the 

 cloud) are so great, that it would be impossible to arrive at 

 satisfactory values, especially in the case of hydrogen, where the 

 weight of the cloud can be as great as |th of the weight of the 

 gas in the same volume. 



(20) Even when the gas has been bubbled through sulphuric 

 acid before entering C, a slight effect of this kind is still to be 

 found. Thus, when the tube is turned from a vertical to a 

 horizontal position, the charge acquired by it per minute increases 

 from 16 to 19 divisions of the electrometer scale per minute. 

 If the coefficient of viscosity can, even roughly, be applied as in 

 section 13 to determine the size of the carrier, the effect of gravity 

 could not exert on a carrier a force that would cause it to move 

 through the gas surrounding it, with a velocity of the same order 

 as g^j centimetres per second. In fact, if we take the density of 

 the carrier to be unity, its radius should be as big as 310 -5 , in 

 order that the force of gravity should make it move with a velocity 

 3^o centims. per second. 



But if, instead of considering a single carrier, we consider the 

 case of a finite quantity of gas (occupying unit volume say), as 

 differing from the surrounding gas by "05 per cent, in density, 

 which could arise from various causes, a vertical motion far greater 

 than the above would ensue, which would affect the discharging 

 power of a horizontal tube. 



The gases can be sent through a tube containing phosphorous 

 pentoxide, after bubbling through sulphuric acid, so as to remove 

 all traces of moisture ; and if the powder is placed loosely in a 

 horizontal tube, about 8 centims. long with glass wool at the end 

 to prevent dust being carried along, not more than half the charge 

 on the gas will be lost. The hydrogen when dried in this manner 

 loses more of its charge, in passing along the vertical tube G, than 

 if it had been dried by sulphuric acid alone ; but the loss of 

 charge was not found to be increased by turning the tube from the 

 vertical to the horizontal position. 



(21) The discharging power of a tube in a vertical position is, 

 as we should expect, greatly diminished by having the gas moist, 

 as the electric force is then too small to have any appreciable 

 effect in causing the drops to move towards the sides. 



