IV CONTENTS. 



ramohalite, by J. Jurasky : Feldspar in the u Orbicular Diorite" of Corsica, by 

 M. Delesse, 113. — On the Products of Eruption at Hecla, by Dr. F. A. Genth : 

 On the Nummulite Limestone of Alabama, by C. Lyell, 114. 



Zoology. — Some Notes on Mexican Birds, heretofore not fully described, by Geo. 

 A. McCall, U.S.A., 114. — Description of new species of Birds, by John Cassin, 

 115. — Otters in Hadley, Mass., 117. 



•Astronomy. — Le Verrier's Remarks on the Planet Neptune, 118. — Eighth Satel- 

 lite of Saturn : Elements of Petersen's Comet of August, 1848, 122. — New 

 Comet : Comet Medal : Some Remarks upon an American Nautical Alma- 

 nac, 123. 



Miscellaneous Intelligence. — Gold in California, 125. — Auroral Bow of April 7, 

 1847, 126.— Aurora Borealis, Nov. 17, 1848, 127.— Relation between the Co- 

 efficient of Elasticity of Metals, and their latent heat of fusion, by C. C. Person, 

 128. — On the Existence of the Color Brown, by Ernest Brucke : Inundation 

 of the Indus, 129. — Flood in the Macquarie, in Australia, 130. — On the Appa- 

 rent Motion of the Figures in certain Patterns of Blue and Red Worsted, by 

 Henry Taylor, 132.— The Tea Plantations in the N.W. Provinces of India, 

 and the Culture of American Cotton in India, 135. — Expedition into Australia : 

 Platinum, 137. — Mines in Australia: The Nile: A Cabinet of Minerals for 

 sale, collected by the late Dr. Crawe, 138. — Obituary. — William Oakes, A.M., 138. 

 Death of Robert Gilmor,Esq.,142. — Dr. Samuel Guthrie : Dr. A. Goldfuss, 143. 



Bibliography. — The Sailor's Horn-Book for the Law of Storms, by Henry Pid- 

 dington, 144. — Memoir, Geographical, Political and Commercial, on the Pres- 

 * ent State, Productive Resources and Capabilities of Siberia, Manchuria, and the 

 Asiatic Islands of the Northern Pacific Ocean, &c.,by Aaron H. Palmer, 148. 

 Memoirs of the American Academy of Arts and Sciences, 149. — An Element- 

 ary Treatise of Spherical Geometry and Trigonometry, by Anthony D. Stan- 

 i.ky, A.M. : The Philosophy of Geology, by A. C. G. Jobert ;— also, Ideas or 

 Outlines of a new System of Philosophy, by A. C. G. Jobert, &c. : Observa- 

 tions on Belemnites and other Fossil Remains of Cephalopoda, discovered by Mr. 

 Reginald Neville Mantell, C.E., in the Oxford clay near Trowbridge, in Wilt- 

 shire, by Gideon Algernon Mantell, Esq., LL.D., F.R.S., F.L.S., &c. : A 

 Memoir on the Structure of the Maxillary and Dental organs of the Iguanodon, 

 by G. A. Mantell, &c, 150. — A Memoir on the Dinornis, by Professor Owen, 

 F.R.S., F.Z.S., &c. &c. : Collections of the Georgia Historical Society: Me- 

 moirs read before the American Association for the Promotion of Science, 151. 



List of Works, 151. 



NUMBER XX. 



Page. 



Art. X. Some New Discoveries respecting the Dates on the great 

 Calendar Stone of the Ancient Mexicans, with Observations 

 on the Mexican Cycle of Fifty-two Years ; by E. G. Sqttier, 153 



XI. On the Comparative Value of different Kinds of Coal for the 

 purpose of Illumination ; and on Methods not hitherto prac- 

 tised for ascertaining the Value of the Gases they afford ; 



by Andrew Fyfe, M.D., F.R.S.E., F.R.S.S.A., - - 157 



