IsO 



Report S.A.A. Advancement of Science. 



POTASSIUM BICHROMATE WITH IODINE ON A 

 ZINC STRIP IN ZINC TUBE. 



lodined salt on zinc and the substances enumerated in class (ii.) 

 (b) behaved in a similar way. The electrification in all these cases 

 at a temperature just below the melting point of zinc was positive, 

 and practically independent of the drop of voltage, between the 

 insulated axial wire and the metal tube with all the voltages used in 

 the experiments. 



These substances were also tried with the second experimental 

 arrangement. The distance between the insulated disc and the 

 substance on the disinsulated zinc disc on the bottom of the vessel 

 was varied from two to eleven centimetres with changing the sign of 

 the electrification. It was found that the sign of the electrification 

 given to the filter (F^,) changed to negative when the temperature 

 was such as to fuse the zinc. 



§7. The carrier of the electric charge. 



In the first experimental arrangement, Fig. IV., Woulff's bottles 

 could be placed between the tube and the filter (F^.). The air was 

 drawn through these wash-bottles singly or in various groups. These 

 wash-bottles were insulated. The following table gives the results 

 obtained in one experiment in which potassium bichromate 

 sprinkled with iodine was placed on zinc. The axial wire was con- 

 nected to case. 



Deviation in Volts 



per Stroke of 



Pump. 



+0-038 

 +0-042 

 -I-0-046 

 -i-0-042 



Air drawn through. 



(1) Water (2) KI solution (3) U-tube with Pumice and H2SO1 



(2) and (3) as above. 

 (2) as above. 

 Nothinp-. 



