Meteorological Observations. 479 



substances ; but the reaction is not complete below 60° to 70° Cent. ; 

 it is even proper to boil the mixture. Long-continued contact of 

 excess of the reagent does not alter the red matter. The author 

 has kept for more than twelve months strongly reddened albumen 

 in contact with excess of the mercurial solution. 



It is to be observed that the reacting power does not reside either 

 in the proto- or pernitrate of mercury, nor even in a mixture of them. 

 It is requisite that the solution which contains these two salts should 

 have nitrous acid added to it ; till this is done, no colour is produced. 

 Pure pernitrate of mercury, saturated with nitrous acid, reacts sen- 

 sibly, but much less than the mixture of the proto- andpersalts satu- 

 rated with the same nitrous acid. Thus the simplest method of pre- 

 paring this solution consists in treating mercury with nitric acid in 

 the method already described. — Ann. de Chim. et de Phys., Aout 1850. 



METEOROLOGICAL, OBSERVATIONS FOR OCT. 1850. 



Chiswick. — October!. Fine: cloudy: clear. 2. Very fine. 3. Slight rain. 

 4, 5. Foggy : very fine. 6. Foggy : very fine : rain. 7. Boisterous. 8. Clear : 

 fine. 9. Slight fog : very fine. 10. Clear: very fine : rain. 11. Windy : stormy 

 showers: clear. 12. Clear: very fine. 13. Overcast. 14, 15. Exceedingly fine: 

 sharp frost at night. 16. Clear and fine. 17. Very fine. 18. Foggy: very 

 fine. 19. Overcast: fine. 20. Fine. 21. Fine: clear and cold. 22. Clear: 

 dense clouds : overcast. 23. Heavy rain. 24. Densely overcast : rain. 25. 

 Cloudy. 26. Clear : cloudy and fine : clear and frosty at night. 27. Clear : fine : 

 rain. 28. Rain : fine : clear. 29. Clear and fine : sharp frost. 30. Frosty : 

 rain: clear. Si. Overcast: fine. 



Mean temperature of the month 44°\32 



Mean temperature of Oct. 1849 49 '55 



Mean temperature of Oct. for the last twenty-four years . 50 '51 



Average amount of rain in Oct 2*67 inches. 



Boston. — Oct. 1, 2. Fine. 3, 4. Cloudy. 5. Fine. 6. Fine : rain p.m. 7. 

 Cloudy: rain early a.m. 8. Cloudy. 9,10. Fine: rain p.m. 11. Cloudy: 

 rain a.m. and p.m. 12. Fine. 13, 14. Cloudy. 15, 16. Fine. 17. Cloudy. 

 18. Fine. 19,20. Cloudy. 21. Cloudy: rain early a.m. 22. Cloudy. 23. 

 Fine: rain a.m. and p.m. 24 — 26. Cloudy: rain a.m. and p.m. 27. Fine: 

 rain p.m. 28. Fine : rain early a.m. 29. Fine. 30. Cloudy. 31. Cloudy: 

 rain early a.m. 



Applegarth Manse, Dumfries-shire. — Oct. I. Fair, but unsettled-looking. 

 2. Fair, but dull, and cloudy. 3. Drizzling greater part of the day. 4. Heavy 

 showers p.m. 5. Fog a.m. : hail: rain p.m. 6. Fog a.m.: heavy rain p.m. 

 7. High wind : heavy rain. 8. Fair, but cloudy. 9. Slight hail : light rain p.m. 

 10. Fair and frosty: shower p.m. 11. Fair and cold. 12. Fair and cold: 

 frost a.m. 13. Moist and drizzly. 14. Slight showers. 15. Frost : high wind p.m. 

 16. Rainy, but slightly so. 17. Slight showers : cleared p.m. 18. Cloudy all 

 day. 19. Slight showers. 20. Clear and fine. 21. Frost a.m. : shower p.m. 

 22. Frost severe: rain p.m. 23. Frost still : shower. 24. Frost severe. 25. Raw: 

 dull : slight shower. 26. Frost hard : fair all day. 27. Frost very hard : ther- 

 mometer 27°: shower p.m. 28. Thaw: fine: clear. 29. Frost again : fine and 

 clear. 30. Rain a.m. : moist all day. 31. Fair and fine throughout. 



Mean temperature of the month , 44 0, 2 



Mean temperature of Oct. 1849 44 '0 



Mean temperature of Oct. for the last twenty-eight years ... 46 *0 



Average rain in Oct. for twenty-three years 3-50inches. 



Sandwick Manse, Orkney. — Oct. 1. Clear: dry: aurora. 2,3. Fine: aurora. 

 4. Fine. 5. Fine : showers : aurora. 6. Fine : solar halo. 7. Rain. 8. Cloudy : 

 showers. 9. Showers : drying. 10. Showers: sleet-showers. 11. Bright: fine. 

 12,13. Drizzle : showers. 14. Showers : sleet- showers. 15. Bright : rain. 16. 

 Rain. 17. Rain : cloudy. 18. Rain. 19. Bright : cloudy. 20. Bright : clear. 

 21. Clear. 22. Cloudy : rain. 23. Showers. 24. Showers: clear. 25. Clear : 

 showers. 26. Clear : frost : fine : aurora. 27. Cloudy : rain : aurora. 28. Bright : 

 clear : aurora. 29. Sleet-showers: fine: aurora. 30. Bain : showers. 31. Bright. 



