of Hydrogen and some other Gases. 319 



phorns pentoxide^ and cotton ; thus the air in the cylinder 

 was entirely free from carbon dioxide, moisture, and dust. 

 The air was then compressed into the measuring tube at a 

 pressure of about 30 atmospheres and subjected to the 

 magnetic measurement. The masses of the gas and the 

 water were determined by weighing. In this case the 

 magnetizing current was usually 4 amperes, and the breadth 

 of the bifilar 1 mm. ; bat by changing the bifilar distance 

 and applying a weaker or stronger field, a moderate deflexion 

 of the scale could be obtained. In the following table one 

 set of observations is shown as an example : — 







Table 



II. 









Sept. 5, 1918 













Air (p=30 atm.) 





Vacuum. 





l h 50™ 



p.m., /=24°-5C 



.,6=60 0. 2 h 35 m p.M. 



,*=24°-8C., 



6=60-0. 



m 



B +«* o =89-0927 



gm. 



m o 



=88-9438 gm. 



C. 



S. 



8. 



C. 



S. 



8. 



amp. 



cm. 



cm. 



amp. 



cm. 



cm. 







56-90 



17-55 







39-40 



0-15 



4 



74-45 



17-79 



4 



39-55 



0-35 







5675 



17-55 







39-20 



0-20 



4 



74-30 



17-60 



4 



39-40 



0-20 







5670 



17-60 







39-20 



0-20 



4 



74-30 



17-70 



4 



39-40 



0-24 







56-60 



17-60 







3916 



0-24 



4 



74-20 



17-70 



4 



39-46 



0-20 







56-50 



17-62 (mean) 







39-20 



0-22 (mean) 



Water. Calculation. 



3 h 35 m p.m., ^=24°-2 C, 6=60-0, d a =17G2-0'22=lT40 cm., 

 - m w +»» =93-1178 gm. <„= -14-64-0-22= -14-86 cm.. 



C. S. f. 



amp. cm. cm. 



61-29 -14 59 Xa = 



m a =0-1489 gm., m n =4-1740 gm., 

 17-40 K 

 0-1489 



4 46-70 -14-70 



61-40 -14-69 -I4 86* 



4 40-71 -14-79 *" 4-1740 



61-42 -14-56 Xa_im 



4 46-86 -14 56 ^ ~ 3^562" 



61-42 -14-62 



4 



X, 



4680 -14-70 X a =23-60xl0-«. 



61-50 -14-64 (mean) 



In the above table h is the breadth of the bifilar expressed 

 in the scale division in the ocular micrometer, 60 divisions 

 corresponding to 1 mm. mo 2 , m , and m w are the masses 

 of oxygen, the tube evacuated, and the water respectively.. 



