PROCEEDINGS OF 

 THE EOYAL SOCIETY. 



vol. xix. No. 128. 



CONTENTS^ IQq 

 April 20, 1871. 



PAGE 



I. Note on the crcumstances of the Transits of Venus over the Sun's Disk in 



the years 2004 and 2012. By J. E. Hind, F.E.S 423 



II. On the Existence and Formation of Salts of Nitrous Oxide. By Edwaed 



Divees, M.D. 425 



III. Eesearch on a New Group of Colloid Bodies containing Mercury, and cer- 

 tain Members of the series of Fatty Ketones. By J. Emeeson Reynolds, 

 Member of the Eoyal College of Physicians, Edinburgh, Keeper of the 

 Mineral Department, and Analyst to the Eoyal Dublin Society . . . .431 



April 27, 1871. 



The Bakeeian Lectuee. — On the Increase of Electrical Eesistance in Con- 

 ductors with rise of Temperature, and its application to the Measure 

 of Ordinary and Furnace Temperatures ; also on a simple Method of 

 measuring Electrical Eesistances. By Chaeles William Siemens, 

 F.E.S., D.C.L 443 



I. On the Change of Pressure and Volume produced by Chemical Combina- 

 tion. By M. Beethelot 445 



II. Eemarks on the Determination of a Ship's Place at Sea. In a Letter to Pro- 

 fessor Stokes. By Gr. B. Aiey, LL.D., &c, Astronomer Eoyal . . . 448 



May 4, 1871. 



I. On the Structure and Affinities of Guy ma annulata, Dune, with Eemarks 

 upon the Persistence of Palaeozoic Types of Madreporaria. By P. Maetin 

 Duncan, M.B. Lond., F.E.S., Professor of G-eology in King's College, 

 London 450 



For continuation of Contents see Mh page of Wrapper. 



