254 



Mr Townsend, On Electricity in Gases [Feb. 8, 



the gas was bubbled through KI solution in the bottle A, and 

 then dried by the sulphuric acid in B (Fig. 3), and led into the 

 paraffin block P. Between P and Q there are two small test-tubes 

 fitted up as shown, the first X containing water and the second Y 

 sulphuric acid ; they were covered with tinfoil F and a ther- 

 mometer T gave the temperature of the tubes. When the 

 thermometer came to a fixed temperature the bath C in which 

 A and B were immersed was adjusted to the same temperature. 

 The gas as it entered P being dry removed from X not only a 

 quantity of vapour to saturate the gas, but also a dense cloud, 

 both the vapour and cloud being removed by the sulphuric acid 

 in Y, so that the gas escaped from Q in the same state as it 

 entered X. The tubes X and Y were weighed before being put 

 into position, and when the temperatures of A and B were made 

 the same as T, a stream of electrified gas was passed through the 

 apparatus for about 10 minutes, during which time the inductor 

 I and the discharger D were alternately connected with the 

 electrometer for periods of two minutes to find the rate at which 

 each was gaining a charge. The tubes X and Y being weighed a 

 second time it was generally found that X lost more weight than 



Y gained, so that it was found necessary to put wool in the upper 

 parts of the tubes, that in X being soaked with water, and that in 



Y with sulphuric acid. The results of these experiments were 

 not quite satisfactory on account of the difference of weight, 

 which occurred chiefly when the stream of gas was irregular, as it 

 sometimes rushed too fast for the sulphuric acid to remove its 

 moisture. On this account the method is only suitable for 

 oxygen, when about 12 or 14 amperes are running through the 

 cell. The results obtained for the negative oxygen were con- 

 sistent, and the numbers shown in the table of observations show 

 that in the process of forming the cloud in X and removing it in 



Y only 21 per cent, of the electrification is lost when the gas is 

 going through at the rate of "85 c.c. per sec. 



In the following table, which gives the result of these experi- 

 ments, 6 is the temperature of the water that the cloud is formed 

 in, T the time in minutes that the stream of gas is allowed to run 

 through X and Y, C the current in amperes through the cell, 

 iVj and X 2 the total charges in divisions of the scale acquired by 

 / and D during the time T, W 1 the loss of weight of X, and W. 2 

 the gain of weight of Y in grammes. 



