1882.] 



Presents. 



455 



tively small and the pressure is such that the occluded contents of the 

 metallic mass forming one terminal would form only a small fraction 

 of the total mass of gas in the tube ; for in that case the pressure, and 

 consequently the appearance of the discharge, would be affected only in 

 an inappreciable degree by the injection of the contents of the ter- 

 minal. It should also be added that, when the terminals are of unequal 

 size, the effects are unequal, as might have been expected. 



The phenomenon in question appears to have so important a bearing 

 on the mechanism of the discharge itself, that it becomes a question of 

 great interest to determine whether the missing gas is to be found in 

 either of the terminals ; and if so, whether the ejection takes place at the 

 positive, and the occlusion at the negative, terminal, or vice versa. For 

 this purpose I have devised a tube with three terminals, but have not 

 yet had time to complete its construction or to make the experiment. 



Presents, March 2, 1882. 



Transactions. 



Eastbourne : — Natural History Society. Transactions. New Series. 



Yol. I. Part 1. 8vo. Eastbourne 1881. The Society. 



Erlangen : — Physikalisch-medicinische Societat. Sitzungsberichte. 



Heft 13. 8vo. Erlangen 1881. The Society. 



Munich: — K. B. Akademie der Wissenschaften. Sitzungsberichte. 



Math.-Phys. 1882, Heft 1. Phil.-Hist. 1881, Bd. II. Heft 3. 



8vo. Munchen 1881-2. The Academy. 



Newcastle-upon-Tyne : — Chemical Society. Transactions. Yol. Y. 



Part 7. 8vo. The Society. 



Public Libraries Committee. Report, 1880-81. 8vo. Newcastle- 



wpon-Tijne. The Committee. 



New York : — American Geographical Society. Journal. Yols. XI, 



XII. 8vo. New York 1879-80. Bulletin. 1881. No. 2. 8vo. 



New York 1881. The Society. 



Prague : — K. Bohmische Gesellschaft der Wissenschaften. Abhand- 



lungen. Polge 6. Band X. 4to. Prag 1881. Sitzungsberichte. 



1879, 1880. 8vo. Prag 1880-81. Jahresbericht. 1879, 1880. 



8vo. Prag 1879-80. Joseph Emler ; Decern Registra Censuum 



Bohemica. 8vo. V. Praze 1881. The Society. 



Rome : — R. Accademia dei Lincei. Transunti. Yol. YI. Fasc. 5. 



4to. Boma 1882. The Academy. 



St. Petersburg : — Academie Imperiale des Sciences. Memoires. 



Tome XXIX. No. 2. 4to. St. Petersburg 1881. The Academy. 

 Tokio : — University. Memoirs of the Science Department. Nos. 4, 



5. 4to. Tokio 2541 (1881). Calendar. 2540-41 (1880-81). 8vo. 



Tokio 2540 (1880). 



The University, per the Japanese Embassy. 



