168 Trans. Acad. Sci. of St. Louis. 



A U-shaped water gauge was mounted in another stop- 

 per of the flask. In the third stopper of the flask a tube 

 with a bulb containing calcium chloride was mounted, 

 this tube being provided with means for connecting the 

 confined air with the outer air. The condensers were 

 wholly removed from the machine. The glass bottle was 

 placed upon a sheet of heavy plate glass. 



When the discharge-knobs of the machine were near 

 enough together so that the brush discharge between 

 them was accompanied by faint disruptive effects, the 

 pressure within the flask could be increased by about 

 two grams-weight per sq. cm., the effect of the negative 

 electrification being somewhat greater than that of the 

 positive. When the knobs were far enough apart to pre- 

 vent disruptive discharges, no luminous effects being 

 observed within the flask, the change in pressure due to 

 either terminal was reduced to between one and two mm. 

 as shown by the water gauge. After the pressure due to 

 electrification of the air had reached a final limit, a trans- 

 fer of the many pointed collector to the front of the other 

 terminal, would result for a time in a slow decrease in 

 pressure, and then in a slow increase to the former 

 limit. The decrease in pressure did not begin until the 

 discharge from the other terminal had begun. Heat ef- 

 fects had been practically eliminated. 



If the gas contains moisture a permanent decrease in 

 pressure at once results, due to condensation of vapor 

 upon the sides of the vessel. 



These results seem to indicate that there is an electri- 

 cal condition of the gas, for which the Boyle-Gay-Lussac 

 constant is a minimum. When this condition is reached, 

 the second term of equation (1) is zero, as applied to 

 molecules of gas. 



An attempt has been made to determine whether or 

 not the value of the gravitation term of Eq. (1) can be 

 affected by electrical action, when the effect represented 

 by the final term is eliminated. The apparatus used was 



