32 
ON OXIDE OF PLATINUM. 
ART. VIII.-PREPARATION OF OXIDE OF PLATINUM. 
By M. Wittstein. 
The author commenced by preparing sulphate of platina 
by dissolving platinum in nitro-muriatie acid, and by after- 
wards heating the mass with sulphuric acid ; for 24 parts 
of platinum, 23 parts of sulphuric acid were taken. 
The liquid was evaporated in a sand-bath, and continually 
stirred; a pulverulent, blackish residue was then obtained, 
which was entirely soluble in water. The sulphuric acid 
was removed by means of nitrate of baryta, and precipita- 
tion was effected by carbonate of lime, and boiling the 
liquor : a brown precipitate was obtained, which was wash- 
ed with acetic acid, to remove the excess of carbonate of 
lime. 
Oxide of platinum, thus prepared, is of a dull brown; it 
detonates when heated. 
By analysing this compound, the author ascertained that 
it should be regarded as a bihydrate, which he represents 
by the following formula: — 
Pt 2 -f H 4 02. 
Ibid, from Buchner's Repertorium. 
