1822.] CoL Beaufoy*s Astronomical Observations. 53 



Oxide of goldj and liquor containing only nine volumes of 

 oxygen. Sudden, brisk effervescence; no heat ; the gold 

 reduced ; and the liquor deoxidized in a short time. 



Oxide of platina in powder , obtained by boiling muriate df 

 platina with soda. Similar action upon concentrated and diluted 

 peroxide of hydrogen as the oxide of gold. 



Oxide of osmium y procured by calcining osmium with chlorate 

 of potash, and highly concentrated peroxide of hydrogen. No 

 sensible action ; but as soon as a small quantity of potash is 

 added, great effervescence ; much heat ; and the clear colour- 

 less liquor becomes of a dark brown. It is uncertain whether 

 the oxide of osmium is reduced. The peroxide diluted with 

 water acts similarly, excepting with less intensity. 



Of the oxides ivhich do not act sensihly, if at ally upon the per- 

 oxide of hydrogen. These are alumina, silica, oxide of chrome, 

 peroxide of tin, protoxide and peroxide of antimony and tungstic 

 acid. 



Several other oxides are undoubtedly similarly circumstanced^ 

 but having had no opportunity of trying them, 1 cannot speak 

 with any certainty. 



Article XI. 



Astronomical Observations, 1821. 

 By Col. Beaufoy, FRS. 



Bushey Heath, near Stanmore, 



Latitude 51° 37' U'3" North. Longitude West in time 1' 20«93". 



Nov. 20. Emersion of Jupiter's first < 9>' 04' 34" > Mean Time at Bushey. 



satellite ( 9 25 55 > Mean Time at Greenwidb. 



Nov. 27. Emersion of Jupiter's first ^ 11 20 19 ? Mean Time at Bushey. 



satellite ( 11 21 40 > Mean Time at Greenwich. 



Nov. 29. Emersion of Jupiter's first ^ 5 49 13 ) Mean Time at Bushey. 



satellite ( 5 50 43 J Mean Time at Greenwich. 



Nov. 29. Emersion of Jupiter's third ^ 6 42 08 ? Mean Time at Bushey. 



satellite ( 6 43 38 $ J\Iean Time at Greenwich, 



Dec. 6. Emersion of Jupiter's first ^ 7 45 20 > Mean Time at Bushey. 



satellite ( 7 46 41 \ JMean Time at Greenwich. 



Dec. 0. Immersion of Jupiter's third ( 8 35 21 > Mean Time at Bushey. 



satellite ( 8 36 42 5 Mean Time at Greenwich, 



