Specific Charge of the Ions emitted by Hot Bodies. 553 



The experiments with the transformer iron led to the 

 numbers in the following table : — 



Transformer Iron. Positive Ions. 



z. 



H. 



V. 



X. 



ejm. 



•569 



4850 



314 



1-525 



535 



•569 



4850 



231 



1-70 



490 



•569 



4850 



147 



2-02 



441 



•555 



4850 



195 



1-50 



356 



•567 



4850 



122 



1-85 



322 



•567 



4850 



194 



1-50 



337 



•567 



4850 



232 



1-35 



327 



•555 



4850 



159 



1-50 



290 



•555 



4850 



3C8 



1-00 



250 



Average 



values ... t 



'/w=372, 



Corrected ... e/m—592. 





m 



/H= 26-0, 



m/R= 164. 



The first three of the above values were given by the same 

 specimen of iron. It will be noticed that they were much 

 higher than any of the others, and we were unable to obtain 

 such high values in any of the subsequent experiments. If 

 these are excluded the mean of the rest gives e\m 305, cor- 

 rected e\m 486, corrected m[K 19*9. The three high values 

 obtained from the first specimen alone give ejm 487, cor- 

 rected ejm 775, corrected m/H 12*5. 



In several of the experiments with iron a black soot-like 

 deposit was observed on the part adjacent to the hot strip 

 after the apparatus had been taken down. This was especially 

 noticeable in the experiments with both kinds of iron in 

 which high values of ejm had been obtained. 



It was thought at one time that the peculiar values of ejm 

 obtained from iron might be due to the magnetic properties 

 of the metal affecting the applied magnetic field. This does 

 not seem to be possible however, since all the experiments 

 were made above the critical temperature at which the ferro- 

 magnetic property disappears. Moreover, it does not seem 

 as though the magnetic properties of the metal had anything 

 to do with the phenomenon, since the value of ejm for 

 nickel, nichrome, and steel (see below), all of which are 

 magnetic, was the same as for the other metals investigated 

 above. 



In fact it seems pretty certain that in the case of iron we 

 have to do with more than one source of positive ionization. 



