vi CONTENTS. 



VII. On the mutual Action of Permanent Magnets, considered chiefly 

 in reference to their best relative Position in an Observatory. By 

 the Rev. Humphrey Lloyd, A.M., Fellow of Trinity College, and 

 Professor of Natural Philosophy in the University of Dublin. 

 F.R.S., V.P.R.I.A., Honorary Member of the American Philo- 

 sophical Society. Eead February 11, 1839 159 



VIII. On the Constant of Refraction, determined by Observations with 

 the Mural Circle of the Armagh Observatory. By the Rev. Thomas 

 EoMNEY Robinson, D.D., M.R.I. A., Member of other Philosophical 

 Societies. Eead January 11, 1841 177 



IX. On the Heat developed during the Combination of Acids and Bases. 

 By Thomas Andrews, M.D., M.R.I.A., Professor of Chemistry in 



the Royal Belfast Institution. Eead January 11, 1841 228 



X. Supplement to a Paper " on the mutual Action of Permanent Mag- 



nets, considered chiefly in reference to their best relative Position in 

 an Observatory!' By the Rev. Humphrey Lloyd, D.D., Fellow of 

 Trinity College, and Professor of Natural Philosophy in the Uni- 

 versity of Dublin. F.R.S., V.P.R.I.A., Honorary Member of the 

 American Philosophical Society. Eead April 26, 1841 249 



XI. Supplementary Researches on the Direction and Mode of Propa- 

 gation of the Electric Force, and on the Source of Electric Deve- 

 lopment. By George J. Knox, Esq. M.R.I A. Eead May 25, 1841. 257 



XII. On Fluctuating Functions. By Sir William Eowan Hamilton, 

 L.L.D., P.R.IA., F.R.A.S., Fellow of the American Society of Arts 

 and Sciences, and of the Royal Society of Northern Antiquaries at 

 Copenhagen ; Honorary or Corresponding Member of the Royal 

 Societies of Edinburgh and Dublin, of the Academies of St. Peters- 

 burgh, Berlin, and Turin, and of other Scientific Societies at Home 

 and Abroad ; Andrews' Professor of Astronomy in the University 



of Dublin, and Royal Astronomer of Ireland. Eead June 22, 1840. 264 



XIII. On the Minute Structure of the Brain in the Chimpanzee, and 

 Human Idiot, compared with that of the perfect Brain of Man; 

 with some Reflections on the Cerebral Functions. By James Ma- 

 cartney, M.D., F.R.S., F.L.S., M.R.I.A., S^c. Sfc. Eead June 27, 

 1842 232 



