346 



Mr Townsend, Electrical Properties of [Nov. 22, 



sulphuric acid cell were first bubbled through a solution of potas- 

 sium iodide in the small flask A and then through distilled water 



Fig. 1. 

 Insulators are drawn with dotted lines and conductors with continuous lines. 



in B. Both A and B were immersed in a trough of water G so 

 that they should remain at a fixed temperature while an experi- 

 ment was being conducted. The charged gas thus formed a cloud 

 and carried it along the delivery tube B, which led into the 

 paraffin block P inside a large metallic screen S. The block P 

 was arranged as shown in the figure in order that the moisture 

 should not break down the insulation by settling on the paraffin. 

 By this means the moist gas. entered the larger tube T connected 

 to three sulphuric acid bulbs F set up between the two paraffin 

 tunnels P and Q. After the gas had bubbled through the acid 

 it was not only cleared of the moisture, which under ordinary 

 conditions it would have carried from B, but the cloud was also 

 completely removed. The increase of weight in the bulbs thus 

 arises from two causes, and when the weight of the moisture 

 necessary to saturate the volume of the gas which passes through 

 F is subtracted from the total, the weight of the cloud is obtained. 

 The gas on leaving F entered one of the insulated inductors, the 

 smaller one O being used for oxygen, and the larger one I for 

 hydrogen. The inductor and the bulbs were both covered with 

 tinfoil and connected to mercury cups in the paraffin block R, so 



