CONTENTS (continued), 



PAGE 



VIII. (I.) On a Tangential Property of Regular Hypocycloids and 

 Epicycloids. (II.) On Theorems relating to the Regular Polyhedra 

 which are analogous to those of Dr. Matthew Stewart on the 

 Regular Polygons. By Henry M. Jefeery, F.R.S. . . . 105 



IX. On the Critical Point of Mixed Gases. By Gerrard Ansdell, 



F. C.S 113 



X. On an Arrangement of the Electric Arc for the Study of the Radia- 

 tion of Vapours, together with Preliminary Results. By G-. D. 

 Liveing, M.A., F.R.S., Professor of Chemistry, and J. Dewar, 

 M.A., F.R.S. , Jacksonian Professor, University of Cambridge . 119 



XI. On the Ultra-violet Spectra of the Elements. Part I. Iron. By 



G. D. Liveing, M.A., F.R.S., Professor of Chemistry, and 

 J. Dewar, M.A., F.R.S., Jacksonian Professor, University of 

 Cambridge 122 



XII. General Observations on the Spectrum of Carbon and its Compounds. 

 By Professor G. D. Liveing, M.A., F.R.S., and Professor James 

 Dewar, M.A., F.R.S 123 



XIII. Further Observations upon Liquid Jets, in continuation of those 



recorded in the Royal Society's "Proceedings" for March and 

 May, 1879. By Lord Rayleigh, F.R.S., Professor of Experi- 

 mental Physics in the University of Cambridge .... 130 



XIV. On a Collection of Rock Specimens from Socotra. By Professor 



T. G. Bonney, M.A., F.R.S., F.G.S 145 



XV. On the Photographic Spectrum of Comet (Wells) I, 1882. By 



William Httggins, D.C.L., LL.D., F.R.S. . . . . .148 



XVI. On the Action of Heat upon the Contagium in the two forms of 

 Septichaeruia known respectively as " Davaine's " and " Pasteur's." 

 By Gr. F. Dowdeswell, M.A. (Cantab.), F.L.S., F.C.S., &c. . 150 



XVII. On the Development of the Enamel of the Teeth of Vertebrates. By 



Emily Nunn. [Plates 2-4] 156 



XVIII. On an Instrument for Correcting Gaseous Volume. By A. Vernon 



Harcourt, M.A., F.R.S 166 



XIX. Sunspots and Terrestrial Phenomena. I. On the Variations of the 



Daily Range of Atmospheric Temperature, as recorded at the 

 Colaba Observatory, Bombay. II. On the Variations of the Daily 

 Range of the Magnetic Declination, as recorded at the Colaba 

 Observatory, Bombay. By C. Chambers, F.R.S., Superintendent 

 of the Colaba Observatory . . 168 



XX. On a Method of Tracing Periodicites in a Series of Observations 



when the Periods are unknown. By Vinayek Naeayeu Nene, 

 First Assistant at £1 e Colaba Observatory, Bombay . . . 168 



XXI. On the Causes of Glacier Motion. By W. R. Browne, M.A., late 



Fellow of Trinity College, Cambridge ...... 168 



