Electrification of the Atmosphere. 



151 



Many experiments were made. The above gives a fair idea 

 of the result. Another solution often employed was an alkaline 

 solution of pyrogallic acid. The effect of this was to reduce the 

 reading slightly when salt and iodine, or lithium chloride and iodine 

 were used. 



The effect was much more marked when (i) potassium iodide 

 and bromine or (2) zinc chloride was used. The following table 

 will give an idea of the results obtained when these substances were 

 used. 



POTASSIUM IODIDE ON WHICH BROMINE HAD BEEN 

 SPRINKLED ON A ZINC STRIP IN A ZINC TUBE. 



Here there is a decided change when the " pyro " and H0SO4 

 are used as traps. Quite as decided an effect was produced with 

 zinc chloride in a zinc tube. 



The experiments were varied by drawing different gases through 

 the tube. The following table gives the results obtained with 



COMMON SALT AND IODINE ON A ZINC STRIP IN A 

 ZINC TUBE:— 



Results with oxygen or carbonic acid gas were not noticeably 

 ■different from those in air. 



§8. Possibility of transmitting the effect from one place to 

 -another. 



