1897.] Newly Prepared Gases. 365 



cylinders, the outer Q was of tin, and the inner P was a porous 

 porcelain vessel fixed by means of corks (G) to the tin cylinder. 

 The porous vessel had one aperture which was fitted with an 

 indiarubber stopper carrying two tubes projecting through 

 the sides of Q at D 1 and D 2 . The tube T was broken, and 

 fitted with a paraffin tunnel for purposes of insulation, and the 

 tube U dipped into a sulphuric acid bottle and so acted as a 

 manometer. 



The outer cylinder had two apertures at E and F, the tube R 

 from E led into a large insulated inductor, and the tube from F 

 was connected through a paraffin tunnel to the delivery tube of 

 a sulphuric acid bottle. 



Before performing an experiment it is necessary to thoroughly 

 dry the whole apparatus, this was done by blowing dry air through 

 T and F. The charged hydrogen from a sulphuric acid electrolyte 

 was dried and allowed to enter the cylinder P through T. 



The bellows is connected to the tube S and a gentle current 

 of air is blown into the cylinder through F. The cylinder Q is 

 connected to earth, and the inductor into which R leads is con- 

 nected to the insulated quadrants of the electrometer. By this 

 means the hydrogen which diffuses through P is carried with the 

 air current along the tube R into the inductor. The sulphuric 

 acid in U during the course of the experiment rose in the tube 

 showing that the hydrogen diffused as quickly as the tube T 

 supplied it. 



Only a very small fraction of the original charge was found to 

 be on the gas after diffusion as the deflection per minute, as the 

 diffused gas enters /, was found to be less than 2°/ of the deflec- 

 tion obtained by allowing the gas to enter / directly. 



(23) Having seen that the hydrogen in diffusing carries with 

 it no appreciable charge it is interesting to know whether the 

 electricity is carried to the sides and gets caught in the pores of 

 the porcelain or whether the carriers remain distributed through- 

 out their original volume surrounded by the air which diffuses 

 in to take the place of the hydrogen. 



In order to test this the whole apparatus was insulated and 

 experiments were conducted as follows : — 



The outside cylinder Q was connected to the insulated quad- 

 rants of the electrometer, and the hydrogen from the cell after 

 bubbling through strong sulphuric acid was admitted into P by 

 means of the tube T. The draught of air between P and Q was 

 maintained in order to make the diffusion as rapid as possible, no 

 inductor was used so that the hydrogen after diffusion was carried 



