204 [LORD KELVIN, DR. M. MACLEAN, AND MR. A. GALT, ON THE 



crossed and the electrification of the air now becomes positive, increasing to a 

 maximum and then diminishing till the zero line is again reached, the air becoming 

 negative again. The air continues to receive negative electrification, on shaking it with 

 the solution, for all further increase of strength of the solution up to saturation. All 

 the acids, all the alkalies except lime water, and all the salts tested, show two zero 



points. 



Curves 7, 8, 9. 



44. Experiments were now tried in which different liquids (500 cub. centims.) 

 and gases (2000 cub. centims.) were shaken up in the bottle, and the electrification 

 of the gas in each case was tested. The following is a tabular summary of the 

 results. In all the experiments, except No. 1, the gas was got into the bottle by 

 displacement of water. The bottle was first filled with water, and inverted in a 

 large trough of water and 2000 cub. centims. of the gas admitted. 



