Meteorological Observations. 519 



base, and may be separated from the oxide of copper and other weak 

 bases by carbonate of baryta, in which process, however, the oxida- 

 tion of the protoxide of copper must be carefully prevented. This 

 method of separation is especially applicable in the analysis of the 

 remarkable double salt consisting of sulphurous acid combined with 

 the protoxide and peroxide of copper. The composition of this salt, 

 ■which has been examined by Fourcroy, Vauquelin, Chevreul, Ber- 

 thier and Muspratt, was first correctly determined by Rammelsberg, 

 who did not overlook the protoxide of copper contained in it.—Bericht 

 der Acadeni. der Wissenschaft . zu Berlin, 1851, p. 102. 



METEOROLOGICAL OBSERVATIONS FOR APRIL 1851. 



CAiOTict.— April 1. Very fine. 2. Slight rain. 3. Cloudy : fine: rain. 4,5. 

 Fine : sharp frost at nights. 6. Cloudy : clear and frosty at night. 7. Cloudy 

 and cold. 8. Showery. 9. Cold rain : clear and frosty. 10. Densely clouded. 

 11. Heavy clouds. 12. Fine : cloudy. 13. Cloudy : clear : slight fro»t. 14. 

 Cold haze. 15. Uniform haze. 16. Slight haze : heavy rain. 17. Cloudy and 

 mild : showery. 18. Cloudy. 19. Very fine. 20. Very fine : rain at night 

 oi Cloudy: rain. 22. Rain. 23. Very fine. 24. Slight haze : clear. 25. Cold 

 haze : cloudy : clear. 26. Foggy : very fine : frosty at night. 27. Cloudy and 

 cold: clear and frosty. 28. Very fine. 29. Showery: clear and frosty.— 30. Fine: 

 showery ; frosty.— Fourteen nights in this month were more or less frosty. 



Mean temperature of the month 44 -56 



Mean temperature of April 1850 48 •41 



Mean temperature of April for the last twenty-five years ... 47 -43 



Average amount of rain in April 1-64 inch. 



Boston.— April 1. Cloudy : rain a.m. and p.m. 2. Rain : rain a.m. 3. Cloudy : 

 rain P.M. 4,5. Cloudy. 6,7. Fine. 8. Fine: rain p.m. 9. Rain: rain a.m. 

 10 Fine: rain A.M. 11— 16. Cloudy. 17. Cloudy : rain early a.m. 18. Cloudy : 

 rain P.M. 19. Fine. 20. Fine : rain p.m. 21, 22. Cloudy. 23— 25. Fine. 

 26. Fine : rain p.m. 27. Cloudy. 28. Fine. 29. Rain a.m. and p.m. 30. Cloudy : 

 rain a.m. 



Avplegarth Manse, Dumfries -shire.— April \. Fair but cloudy. 2. Dull and 

 showery" 3. Fair and fine : very mild p.m. 4. Fair and fine. 5. Fair a.m. : a 

 few drops p.m. 6. Fair and fine. 7. Fair : dull. 8. Fair : clear p.m. 9. Fair : 

 eray cold. 10. Frost hard: clear and fine. 11. Frost : dull : clear p.m. 12. 

 Cold but not frost: a few drops. 13. Frost gentle: cold p.m. 14. Frost keen : 

 droughty. 15. No frost : cold and dry : a few drops. 16. Frost again : keen : 

 cloudy P.M. 17. Heavy rain nearly all day. 18. Rain : very beneficial. 19. 

 Frequent showers p.m. 20. Fair till nine p.m. : rain. 21. Fair all day, but 

 cloudy. 22. Showers a.m. and p.m. 23. Remarkably fine day. 24. Re- 

 markably fine day: thunder. 25. Thunder again: a few drops. 26. Slight 

 shower of snow: rain p.m. 27. Slight shower of snow : frost a.m. 28. Frost: 

 a few drops of rain p.m. 29. Cold : keen : frequent showers : thunder : sleet on 

 hills. 30. Cold, but no frost : a few drops. ^ 



Mean temperature of ihe month 43 -7 



Mean temperature of April 1850 46-3 



Mean temperature of April for twenty-nine years 44 -3 



Average rain in April for twenty-four years 1-81 inch. 



Satidwic/t Manse, Orlniei/.— April 1. Cloudy. 2. Clear : fine a.m. 3. Fine a.m. 

 4 5 Fine. 6. Drops : fine : drops 7. Fine. 8. Fine : cloudy. 9— 12. Fine. 

 13 Drops: drizzle: showers. 14— 16. Cloudy. 17. Bright : cloudy. 18. Fog: 

 showers. 19. Bright : clear a.m. 20. Cloudy. 21. Drops : rain : clear. 22. 

 Cloudy : showers : clear. 23. Drizzle : showers ; clear. 24. Cloudy : damp. 

 25. Cloudy : sleet-showers. 26, 27. Sleet-showers : hail-showers. 28. Sleet- 

 showers. 29. Rain : cloudy. 30. Clear : rain. 



