544 Meteorological Observations. 



ON PLATINA. BY J. W, DOBEREINER. 



When native platina is fused with twice its weight of pure zinc, 

 this alloy, after cooling, pulverizes ; and put into moderately dilute 

 sulphuric acid until the action has ceased, and then heated with very 

 dilute nitric acid, assisted by heat, a residue is obtained which, after 

 washing with water, consists of undissolved iridium, osmium, and, in 

 silver coloured grains, a heavy blackish-grey powder, composed of 

 platinum, palladium, iridium, rhodium, and osmium. 



This compound metallic powder possesses the same properties as 

 the phitina separated from its alloy of potassium or iron, which J.W. 

 Dcibereiner has examined and frequently described. It absorbs and 

 condenses oxygen gas, and is such an oxidizing agent, that it not only 

 converts the oxalic and formic acids into carbonic acid, and alcohol 

 first into acetal, next into aldehyd, and then into acetic acid, but also 

 'converts the contained osmium into osmic acid, which sublimes at a 

 gentle heat, or can be dissolved out by an alkaline solution. In the 

 latter case the oxidizing properties of this metallic powder are still 

 increased, and a preparation obtained which not only suddenly ignites 

 hydrogen gas, but also the vapours of pyroxylic spirit and alcohol, 

 and detonates when heated on platina foil, a property Descotils pointed 

 out fifty-five years ago, but which has not been since noticed. 



This powder is dissolved in aqua regia nearly as easily as gold. 



Muriatic acid destroys its property of absorbing oxygen gas; so that 

 it ceases to detonate on heating, or to act metallically (me)alylisch, 

 or as Berzelius calls it,, catalylisch,)on the above substances : however, 

 by heating it with a solution of a fixed alkali, its former power is re- 

 stored. — Foggendorff''s Annals. 



METEOROLOGICAL OBSERVATIONS FOR OCTOBER 1836. 



Chiswlck. — Oct. 1, 2. Stormy with rain. 3. Heavy rain: boisterous = 

 clear and frosty at night. 4. Frosty : fine. 5. Hazj : very fine. 6. Hazy, 

 with rain. 7. Overcast : rain. 8. Dense clouds : rain at night. 9. Clear 

 and fine. 10. Heavy rain. 11 — 13. Boisterous. 14. Fine. 15. Showery. 

 16 — 18. Foggy. 19. Very fine. 20 — 26. Foggy in the mornings : fine. 

 27. Showery : clear and cold. 28. Cloudy and very cold : north-west wind. 

 29. Snow. 30. Clear: snow yet remaining on the ground. 31. Sharp 

 frost : fine. The depth of snow on the morning of the 29th was nearly 

 three inches ,- and during the day there were stormy showers of snow in 

 very broad flakes. Notwithstanding the brii;ht sunshine on the following 

 day, the snow generally still continued to cover the ground. 



Boston.— Oct. l.R^^m. 2. Cloudy. 3. Rain. 4, 5. Fine. 6. Fine: 

 rain r.M. 7. Fine. 8. Cloudy. 9. Fine : rain early a.m. 10. Rain. 

 1 1. Stormy : very stormy night : rain early a.m. 12. Fine. 13, 14. Cloudy. 

 15. Cloudy : rain early A.M.: rain A.M. 16. Fine. 17. Cloudy. 18. Cloudy: 

 rain P.M. 19, 20. Fine. 21, 22. Cloudy. 23. Fine. 24. Foggy. 

 25. Cloudy. 26. Fine. 27. Stormy : rain early a.m. 28. Fine: ice this 

 mornino'. 29. Snow : snow six inches deep. 30. Fine : hail-storni early 

 A.M. 31. Fine : great deal of snow on the ground. 



Our Correspondent Mr. Veall adds the following note: 

 " I am in possession of journals of the vveather kept at Boston during 

 the last twenty years, but do not find -such a fall of snow recorded in the 

 month of October." 



