ix 



No. 449. 



Page 



The Mechanism of the Electric Arc. By (Mrs.) Hertha Ayrton. Com- 

 municated by Professor Perry, F.E.S 410 



Eeport of Magnetical Observations at Falmouth Observatory for the 

 Year 1900 415 



The National Physical Laboratory. Eeport on the Observatory Depart- 

 ment for the Year ending December 31, 1900 421 - 



The Stability of a Spherical Nebula, By J. H. Jeans, B. A., Scholar of 

 Trinity College, and Isaac Newton Student in the University of 

 Cambridge. Communicated by Professor G. H. Darwin, F.E.S 454 



The Spectrum of n Argus. By Sir David Gill, K.C.B., LL.D., F.E.S., 

 H.M. Astronomer at the Cape (Plate 4) 456 



Croonian Lecture. — Studies in Visual Sensation. By C. Lloyd 

 Morgan, F.E.S., Principal of University College, Bristol 459 



The Yellow Colouring Matters accompanying Chlorophyll and their 

 Spectroscopic Eelations. Part II. By C. A. Schunck. Commu- 

 nicated by Dr. E. Schunck, F.E.S. (Plates 5, 6) 474 



No. 450. 



On Skin Currents. — Part I. The Frog's Skin. By Augustus D. Wal- 

 ler, M.D., F.E.S 480 



Virulence of Desiccated Tubercular Sputum. By Harold Swithin- 

 bank. Communicated by Sir James Crichton Browne, F.E.S. 495 



Effect of Exposure to Liquid Air upon the Vitality and Virulence of 

 the Bacillus Tuberculosis. By H. Swithinbank. Communicated by 

 Sir James Crichton Browne, F.E.S. 498 



On the Behaviour of Oxy-hasmoglobin, Carbonic-oxide-hsemoglobin, 

 Methsemoglobin, and certain of their Derivatives, in the Magnetic 

 Field, with a Preliminary Note on the Electrolysis of the Haemo- 

 globin Compounds. By Arthur Gamgee, M.D., F.E.S., Emeritus 

 Professor of Physiology in the Owens College, Victoria University.... 503 



On the Eesistance and Electromotive Forces of the Electric Arc. By 

 W. Duddell, Whitworth Scholar. Communicated by Professor W. 

 E. Ayrton, F.E.S 512 



Index 519 



