Oxides of Platinum and Gold, 11 
rated from the metal by water, and the platinum weighed. A 
hundred parts of this double salt gave 
Oxymuriatic gas, or chlorine, - - 29.2 
Platinum, , ^ - 40.0 
Muriate , of potash, • « . - 30.8 
100.0 
The muriatic acid, abandoned by the oxide of platinum, 
makes twice the quantity of the same acid in the muriate of po- 
tash remaining ; consequently the double salt is composed of 
one atom of muriate of potash, and two atoms of the permuriate 
of platinum, or, if we prefer it, of one atom of the chloride of 
potassium, and two atoms of the perchlorure of platinum. In 
calculating from the Tables of M. Berzelius, the quantity of 
platinum in this salt, we shall find it to be 40.066. 
M. Berzelius has also analysed the double muriate of pla- 
tinum and soda, and has found it to be composed of one atom 
of muriate of soda, two atoms of the permuriate of platinum, 
and twelve atoms of water, that is to say, it contains of pla- 
tinum 19.25 hundredths of its weight. 
b. Oxide of Gold. 
M. Pelletier, in his interesting memoir on the chemical na- 
ture of the oxide of gold, has examined the properties and the 
composition of the ioduret of gold, and concludes from this last, 
that the atom of gold should weigh 29-93, instead of S4.86, as 
follows from the experiments of M. Berzelius. In a new in- 
vestigation, for the purpose of examining the assertion of M. 
Pelletier, M. Berzelius decomposed the neutral muriate of gold, 
by carbonate of soda in excess. Having evaporated the mass to 
dryness, it was brought to a red heat, and being re-dissolved by 
water left metallic gold. The solution was neutralised by the ni- 
tric acid, and precipitated by the nitrate of silver. In this manner 
M. Berzelius found the weight of gold to be a little lighter than 
formerly, but he attributed this to the great tendency of the 
muriate of gold to form a supermuriate, by the successive re- 
duction of the oxide of gold dissolved. On this occasion he 
shews, that the oxide of gold forms with the muriatic acid two 
combinations, one of which is a deep red, even when dissolved 
