CONTENTS. 



On Mr. BuRNs's Method of fading the Latitude by Double 

 Altitudes. By Thomas Henderson, Esq. . . . 283 



Examination of the Platina found in Russia. By M. Lau- 

 GIER 285 



Analysis of an Urinary Calculus from a Hog. By M. Wur- 

 ZER, of Marburg 288 



On the Solution of' various Kinds of Steel andiron in Acids ; and 

 on the Nature of the Residuums left by them. By M. Kar- 

 STEN 290 



Extract from a Letter addressed by Professor Bessel to Pro- 

 fessor Schumacher, relating to the Green-mch Observations, 

 as criticized in the Philosophical Magazine fo^- November and 

 December 1824 292 



On the Variatioti of Density and Pressure in the interior Parts 

 of the Earth. By J. Ivory, Esq. M.A.F.R.S. ... 321 



0?i the unequal Evolution of Heat in the Prismatic Specti-um. 

 By Dr. T. J. Seebeck 330, 445 



Reply to the Observations of Mr. Riddle and Mr. Henderson 

 on Mr. Burns's Mode of finding the Latitude by Doiible Al- 

 titudes. By James Burns, Esq 344 



Report of the Transactions of the Academy of Natural Sciences 

 of Philadelphia during the Year 1824; subinitted by the Re- 

 cording Secretary, in pursuance of a Resolution of the Aca- 

 demy 346, 439 



Reply to Mr. Davies's " Further Thoughts on Mr. Herapath's 

 Demonstration." By P. Q 354 



Researches on the Composition of Peridot. By L. P. Walm- 

 stedt 357 



A Letter from M. Ampere to M. Gerhardi on various 

 Electro-dynamic Phcsnomena 368 



Memoir on a new Electro-dynamic Experiment, on its Applica- 

 tion to the Formula representing the mutual Action of the two 

 Elements of Voltaic Conductors, and on some new Residts 

 deduced from that Fornmla. By M. Ampere . . . 373 



On the Anatomy of the Mole-cricket. By J. Kidd, M.D. and 

 F.R.S. Reg. Prof of Medicine in the University of Oxford 



401 



On the Theory of the Figure of the Planets contained in the 

 Third Booh of the Mecanique Celeste. By J. Ivory, Esq. 

 M.A. F.R.S. 429 



Strictures by Robert Hare, M.D. Professor of Chemistry, 

 Sfc. Sfc, upon Professor Vanuxem's Memoir on Plumbago, 

 Anthracite, Fused Carbon, S)-c., published in the Journal of 

 the Academy of Natural Sciences for June 1 825 . . 455 



Remarks on Mr. Burns's Reply on the Dotible Altitude Pro- 

 blem. By E. Riddle, Esq 458 



