472 Perkins — Molecular Weight of Radium Emanation. 



Feb. 13, at 250 ? C. 

 Time Aint. of Hg Calculation 



Feb. 14, at 250° C. 

 Time Amt. of Hg Calculation 





diffusing 



for A- 





diffusing 



for h 



20 



•0050 





20 



•0817 





20 



•0489 



•0489 20* 



20 



•0531 



•0531 20* 



=e 



•025 I 





•0231 



20 



•0231 



.-. *='0374 



20 



•0251 



.-. *=-0374 



20 



•0110 



•0231 20* 



20 



•0120 



•0251 20* 





•0110 



•0120 







.-. * = -037l 







.-. *=*0369 



Feb. 15, a. m., 250° C. 

 Time Amt. of Hg Calculation 

 diffusing for k 



20 



•0658 





21 



•0548 



•0548 ■ 21* 

 •0249 _ 



21 



•0249 



.-. *=-0375 



21 



•0112 



•0249 21* 





•0112 







.-. *=-0379 



Feb. 17, a. m.. 275° C. 

 Time Amt. of Hg Calculation 



Feb. 15, p. m., 275° C. 

 Time Amt. of Hg Calculation 

 diffusing for k 



20 -1440 



20 



20 



•0682 



•0296 



0682 



20* 

 0296~ e 

 -. * = -0416 

 0296 20* 



=e 



0131 



*=0408 



Feb. 17, p. m., 275° C. 

 Time Amt. of Hg Calculation 





diffusing 



for k 





diffusing 



for k 



20 



•1414 





20 



•1233 





20 



•0700 



•0700 20* 



22 



•0589 



•0589 22* 





•0306 



•0246 







.-. *=-0414 



-*■ 





.-. * = -0397 



20 



•0306 



•0306 20* 



22 



•0246 







•0138 





20 



•0138 



.-. * = -0399 









.Resume. 

 Following is a brief review of the data in the order obtained : 



(1) Four experiments at 250° C. with emanation. * = -0338 ± 



•00025. 



(2) Two experiments at 275° C. with emanation. * = *0376 ± 



•00040. 



(3) A series at 250° C. with a constant supply of tmrcuiy vapor 



in the diffusion chamber. Average amount per min. = 

 •00450 ± -000012. 



(4) One experiment at 250° C. with mercury vapor by Method 



II. * = -0366. 



(5) Two experiments at 250° C. with emanation. * = -0344 + 



•00026. 



(6) Three experiments at 250° C. with mercury by Method II. 



* = -0374 ± -00009. 



