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XXVII. On the Absorption of Gases in Vacuum- Tubes. 



To the Editors of the Philosophical Magazine. 

 Gentlemen, — 



WE shall be much obliged if you will permit us to add a 

 note to our paper on "Absorption of Gases in Vacuum- 

 Tubes, <fcc," published in the May issue of the Philosophical 

 Magazine. After the publication of our paper we received 

 copies of a paper by Dr. L. Vegard entitled " Uber die 

 elektrische Absorption in Entladungsrohren," Videnskaps- 

 selskapets Shifter, I. Mat.-naturv. Klasse, 1913, No. 7 r 

 Kristiania. We regret that we had no access to this paper, 

 as Dr. Vegard to a certain extent anticipated some of our 

 results. The preliminary account of Dr. Vegard's work was 

 published in the Philosophical Magazine, xviii. 1909, p. 465. 

 However, owing to the form of the title — " Electric Discharge 

 through HClj HBr, and HI," — the possibility that the paper 

 might have any reference to our work escaped our notice. 



As affecting the subject of our paper, we should like to> 

 mention that Dr. Vegard found that there was no absorption 

 — except for a little which he calls " non-conservative " — 

 with normal cathode-fall, whilst with abnormal fall the rate 

 of absorption increased with increasing fall for nitrogen, 

 oxygen, and helium, but not for hydrogen. Dr. Vegard 

 also suggests that there is some connexion between absorption 

 and disintegration of the cathode. We have much pleasure 

 in acknowledging Dr. Vegard's priority in these results. 



Dr. Vegard suggests that the absorbed gas enters into 

 combination — " due to a new kind of combining power 

 called ' electric affinity ' " — with the disintegrated particles- 

 of the cathode. 



Yours faithfully, 



Physics Department, S. BRODETSKY, 



Umjenrity of Bristol. B HODGSON. 



May 22nd, 1916. 



XXVIII. On the Electric Absorption of Gases in 

 Vacuum- Tubes. 



To the Editors of the Philosophical Magazine. 

 Gentlemen, — 



IX the number of the Phil. Mag. for May this year 

 Dr. S. Brodetsky and Dr. B. Hodgson have published 

 an interesting paper on the absorption of gases in vacuum- 

 tubes and allied phenomena. In this connexion I should 

 like to call the attention of the authors to some papers 



