IV CONTENTS. 



Page 

 on the Occultation of the Planet Herschel by the Moon. 4. Fifth Comet ot' 

 1825 in Etidanus. 5. Second Comet of 1825 in Taurus. 0. First Comet of 

 1826, or the lost Comet of 1772- 7- Ellipticity of the Earth at Port Bowen. 

 8. Double Star 61 Cygni, - 177—180 



Optics 9. Effect of the Sun's light in diminishing Combustion. 10. Sin- 

 gular Phenomenon observed by M. Ramond on the Pic du Midi. 11. On 

 the Powerful Effect of Burning-Glasses at great Heights, - 180 — 181 



Magnetism 12. Diurnal Variation of the Needle in the Arctic Regions, 181 



Meteorology 13. Meteorological Observations on the 17th of July next, ib 



II. CHEMISTRY. 



14. Dr Henry's Analysis of a Crystalline Compound of Hyponitrous and Sul. 

 phuric Acids. 15. On the Air contained in River and Canal Waters. 16. 

 Substances which accompany Caoutchouc when obtained from the Tree in 

 the state of Sap. 17. On the Nature of Picrotoxine and Menispermic Acid. 



18. Prize Questions of the Parisian Society of Pharmacy for 1826, 181 — 185 



III. NATURAL HISTORY. 



Mineralogy. 19. Selenium found in Bavaria. 20. Uran-bloom, a new mU 



neral species. 21. New Localities of Rare Minerals. Leyvne. 22. Comp- 

 tonite. 23. Brewsterite. 24. Selenium from Lukawitz in Bohemia. 25. 

 Zircon found at Scalpay in Harris, - - 185 — 187 



Zoology 26. Two-Headed Snakes. 27- Mercantile importance of Snails. 



Botany 28. Botany of New South Wales. - 188 



IV. GENERAL SCIENCE. 



29. The waters of Salt Springs raised by Carburetted Hydrogen Gas, in the 

 State of Ohio, - - 189 



XLI Meteorological Observations made at Leith, By Messrs Cold- 



stream and Foggo. Communicated by the Authors, - 190 



XLII. Celestial Phenomena, from July 1st, to October 1st 1826, adapted to 



the Meridian of Greenwich, Apparent Time, - 192 



XLII I. Register of the Barometer, Thermometer, and Rain-Gage, kept at 



Canaan Cottage. By Alex. Adie, Esq. F. R. S. Edin. - 194 



