Meteorological Observations. 407 



Ural, analysed by Hermann, are nearly equal according to his analysis ; 

 according to the author's, their proportion in SiO' : R^O^ : MgO : HO 

 is rather as 3 : 1 : 2 : 2. Consequently steatite from the Ural would 

 be (MgO)6, Si03 + (Al^ O^y, SiO^ + 6H0. The Norwegian steatite, 

 on the contrary, would be 2(MgO)3, SiO^ + Al^ O^, Si03 + 6HO. 

 This formula is the same as that deduced by Hartwall from his ana- 

 lysis for the Kammererite of Bissersk. — Poggendorff's Annalen, 

 vol. xcvii. p. 296. 



PREPARATION OF PEROXIDE OF LEAD BY MEANS OF FERRID- 

 CYANIDE OF POTASSIUM. BY DR. A. OVEKBECK. 



The solution of ferridcyanide of potassium is boiled with hydr'ated 

 oxide of lead and potash until the oxide of lead is converted into 

 peroxide. The solution which remains after the conversion furnishes 

 ferrocyanide of potassium. 



KO -I- PbO + K3 Fes Cy 6 give PbO« + 2 (K^ Fe Cy^) . 

 — Archiv der Pharmacie, vol. Ixxxv. p. 5. 



METEOROLOGICAL OBSERVATIONS FOR MARCH 1856. 



Chimick.—UAxch \. Cloudv : fine. 2. Cloudy : slight rain. 3, 4. Cloudy and 

 cold. 5. Overcast. 6. Cloudy and cold : fine. 7. Cloudy : fine. 8. Fine : slight 

 rain. 9. Cloudy. 10. Foggy: fine. 11. Foggy: hazy: frosty at night. 12. 

 Clear and frosty : cloudy and windy. 13. Cold and dry. 14. Excessively cold 

 wind : clear, cold and dry. 15. Cloudy. 16. Slight haze : heavy rain at night. 

 17. Hazy. 18. Hazy: fine rain. 19,20. Hazy: overcast. 21. Hazy: cloudy. 

 22. Overcast : fine. 23. Hazy : fine : clear. 24, 25. Hazy and cold. 26. Cloudy 

 and cold. 27. Clesu: : fine : frosty. 28. Cloudy and cold. 29. Dry cold haze : 

 frosty at night. 30. Slight haze : fine : sharp frost. 31. Slight haze : very fine : 

 frosty. 



Mean temperature of the month 38°"95 



Mean temperature of March 1855 37 "61 



Mean temperature of March for the last thirty years 42 "09 



Average amount of rain in March 1344 inch. 



Boston.— U&xch 1, 2. Cloudy. 3. Cloudy : rain p.m. 4, 5. Cloudy. 6. Cloudy: 

 rain A.M. 7—9. Fine. 10. Cloudy. 11. Cloudy: snow a.m. 12,13. Cloudy. 



14. Fine. 15. Cloudy. 16. Fine. 17. Cloudy : rain a.m. and p.m. 18. Cloudy : 

 rain P.M. 19. Cloudy : rain a.m. 20. Cloudy. 21. Cloudy : rain a.m. and p.m. 

 22—26. Cloudy. 27. Fine. 28. Cloudy. 29—31. Fine. 



Sandwich Manse, Orkney. — March 1. Cloudy a.m. : fine, drizzle p.m. 2. Drizzle 

 A.M. : fine, cloudy p.m. 3. Damp a.m. : fine, clear p.m. 4. Showers, fine a.m. : 

 fine, cloudy p.m. 5. Damp a.m. : fine," aurora p.m. 6. Drops a.m. : fine p.m. 

 7. Fog A.M. and p.m. 8. Showers a.m. : fine, aurora p.m. 9. Showers a.m. : 

 cloudy P.M. 10. Frost a.m. : clear, frost p.m. 11, 12. Snow-showers a.m. and 

 P.M. 13. Snow, frost a.m. : clear, frost p.m. 14. Clear, frost a.m. : very clear p.m. 



15. Bright a.m.: very clear, aurora p.m. 16. Clear a.m.: very clear p.m. 17. 

 Bright a.m. : cloudy p.m. 18. Cloudy a.m. and p.m. 19. Bright a.m. : cloudy 

 P.M. 20,21. Cloudy, fine A.M. and p.m. 22. Bright, fine a.m. : clear, fine p.m. 

 23, 24. Cloudy a.m. : cloudy, fine p.m. 25. Cloudy a.m. : clear, fine p.m. 26. 

 Bright a.m. : cloudy, fine p.m. 27. Bright a.m. : clear, aurora p.m. 28. Cloudy 

 A.M.: very clear, fine p.m. 29. Clear a.m. : very clear, fine p.m. 30. Cloudy 

 a.m. : very clear, fine, aurora p.m. 31. Bright a.m. : cloudy, fine p.m. 



Mean temperature of March for previous twenty-nine years... 40°'40 



Mean temperature of this month 40 '39 



Mean temperature of March 1855 36 '61 



Average quantity of rain in March for fifteen previous years . 2*60 inches. 



This month has been unprcccdentedly dry, the rain being only about one-eighth 



of the average for .March, and less than that of any month during my observations, 



except April 1852, when it was only '11 of an inch. Rain_fell only on eight days. 



