248 Mr Townsend, On Electricity in Oases [Feb. 8, 



sulphuric acid at about 80° is poured over two or three grammes 

 of iron wire that the electrometer first shows that a large positive 

 charge is escaping from A, and, as the process of dissolving goes 

 on for a few minutes, that the escape of positive electricity gets 

 less and less till finally a neutral stage is reached, and immediately 

 after this negative electricity in large quantities begins to escape 

 and continues to do so till all the iron is dissolved. From this 

 Enright concluded that at one time positive and at another time 

 negative electricity was carried by the gas. Further examination 

 however does not justify this conclusion, for if instead of letting 

 the gas escape into the air from A it be made to pass through the 

 liquids in B and G and escape by the tube T into the air it will be 

 now found that G loses positive electricity as before, reduced in 

 quantity, whereas none of the negative which in Enright's experi- 

 ment is the larger of the two charges will now escape with the 

 gas. We see therefore that there is no evidence here that the 

 hydrogen carries the negative electricity, and that it is more 

 probable that this charge was carried by the spray which it 

 acquired by an inductive effect. 



8. The gases which are given off by electrolysis have always 

 been assumed to be completely cleared of electricity. It does not 

 require a very delicate electrometer to show that this is not the 

 case; for if they are examined by any of the ordinary methods it 

 will be found that under certain circumstances these gases carry a 

 large charge which remains on the gas after it has been passed 

 through wool or bubbled through a liquid, and owing to the regu- 

 larity with which they can be produced, by keeping the current 

 through the electrolyte constant, the method affords an extremely 

 simple means of studying the properties of charged gases. 



9. As far as experiments which I have already made on this 

 subject show, it is possible to obtain gases with any electric density 

 up to 5 x 10 -3 electrostatic units. This has been found to be the 

 case with regard to positively charged oxygen and hydrogen which 

 are given off when dilute sulphuric acid is electrolysed, and also 

 with regard to the negative oxygen which is given off from a 

 caustic potash cell. The hydrogen from the latter also has a 

 negative charge, but it is small compared with that which is on the 

 oxygen, whereas in the case of the sulphuric acid cell the hydrogen 

 as a rule has the larger charge. The effects are in all cases 

 increased by raising the temperature of the cell. The charge and 

 sometimes even the sign is altered by impurities, but it is not 

 proposed here to enter into details concerning the electrolytes. 

 Suffice it to say that the positive gases are got from sulphuric 

 acid, and the negative from a caustic potash solution when a 



