Meteorological Observations, 407 



tion is very distinct. This compound is white ; on treating it with 

 potash, there are produced ferrocyanide of potassium and yellow 

 oxide of mercury, insoluble in excess of potash. — L'Institut, Avril 10, 

 1850. 



EQUIVALENT OF CHROMIUM. BY M. LEFORT. 



According to Berzelius, the equivalent of chromium is 35 1 ; other 

 chemists make it 320 and 330 : according to M. Lefort, the equiva- 

 lent is 333.— /6irf. 



METEOROLOGICAL OBSERVATIONS FOR MARCH 1850. 



Chiswick. — March 1. Hazy : very fine : overcast. 2. Densely overcast. 3. 

 Cloudy. 4. Cloudy : clear and frosty at night. 5. Frosty : fine : cloudy. 

 6,7. Foggy : fine : clear. 8. Hazy. 9. Slight fog : fine : clear. 10. Very fine. 

 11. Clear and fine: frosty. 12. Frosty: very fine : clear. 13. Frosty, with 

 slight fog : very fine. 14. Overcast. 15. Overcast: clear, with sharp frost at night. 



16. Frosty : overcast : clear, 17. Frosty: cloudy: sunshine occasionally: clear and 

 frosty. 18. Frosty and fine, 19,20. Cloudy. 21. Cloudy and cold : clear and 

 frosty. 22. Hoar-frost : cloudy. 23. Heavy clouds : sleet-showers. 24. Slight 

 fall of snow-flakes: severe frost at night. 25. Clear and frosty : cloudy: clear: 

 frosty. 26. Overcast. 27. Foggy : slight haze : frosty. 28. Slight haze : bright 

 sun with dry cold air : clear and frosty. 29. Foggy: cloudy: clear. 30,31. 

 Overcast. 



Mean temperature of the month 37°*71 



Mean temperature of March 1849 41 '56 



Mean temperature of March for the last twenty-three years 42 "81 



Average amount of rain in March 1*36 inch. 



Boston. — March 1,2. Cloudy. 3. Fine : rain p.m. 4. Cloudy. 5 — 7. Fine. 



8,9. Cloudy. 10. Fine. 11. Cloudy. 12,13. Fine. 14,15. Cloudy. 16. 



Cloudy : rain A.M. 17,18. Fine. 19. Cloudy: rain a.m. 20. Cloudy. 21. 



Fine. 22. Cloudy. 23. Fine: rain early a.m. 24. Cloudy: snow a.m. and p.m. 



25. Cloudy. 26,27. Fine. 28. Fine : rain a.m. 29,30. Fine. 31. Cloudy: 



rain a.m. 



Applegarth Manse, Dumfries-shire. — March 1. Fine: a shower early a.m. 2. 



Slight shower during night : thick p.m. 3. Rain heavy a.m. : cleared. 4. Frost : 



clear and fine. 5. Moist all day. 6. Mild and growing : moist. 7. Fine spring 



day. 8. Still finer: clear and warm. 9. Dull and moist : slight shower. 10. 



Clear and fine: slight shower. 11. Frost : clear and bright. 12. Frost : cloudy. 



13. Frost, not so severe. 14, 15. Mild: cloudy: no frost. 16. East wind: dull. 



17. Dull : raw : cold : shower. 18. Dull and cloudy, but mild. 19. Dull a.m. : 

 cleared: rain P.M. 20. Very fine : slight drizzle. 21. Fine, though raw a.m. 

 22. Dry, but cloudy : stormy P.M. 23. Frost: snow: wind. 24. Hard frost : 

 snow : calm P.M. 25. Frost very hard : thermometer 21^°. 26. Frost slight : 

 heavy snow a.m. 27. Frost severe : snow again. 28. Frost still harder : clear. 

 29. Frost still. SO. Frost moderate : hail : rain p.m. 31. Rain : cloudy and 

 foggy p.m. 



Mean temperature of the month 40°'3 



Mean temperature of March 1849 41 '8 



Mean temperature of March for the last twenty-eight years. 39 '6 



Average rain in March for twenty-three years 2*35 inches. 



Sandtuick Manse, Orkjiey. — March 1. Showers: drops. 2. Drizzle. 3. Cloudy: 

 showers. 4. Snow : cloudy. 5. Damp : rain. 6. Drizzle : cloudy. 7. Damp. 

 8. Fine : drizzle. 9. Cloudy : showers. 10. Sleet : aurora. 11. Bright: clear : 

 aurora. 12. Drizzle. 13. Damp: drizzle. 14. Drizzle: damp. 15. Bright: 

 damp. 16. Cloudy. 17. Drops : showers. 18. Hazy: cloudy. 19. Cloudy. 

 20. Bright : drops. 21. Cloudy: drops. 22. Showers: snow-showers. 23. 

 Hail-showers : snow-showers. 24. Snow-drift : snow-showers. 25. Snow- 

 showers : large halo. 26. Snow- showers. 27,28. Bright: snow-showers. 29, 

 Bright : clear, 30, Cloudy, 31, Drops : cloudy. 



