1819.) the Oxygenized Acids and Oxides. 9 
Articte III. 
Fifth Series of Observations on the Oxygenized Acids and Oxides.* 
By M.Thenard. (Read to the Academy of Sciences Oct. 5, 
1818.) 
Tue facts, of which this series of observations consist, are so 
remarkable that they will probably excite some surprize in the 
most distinguished chemists. I shall state them as concisely as 
possible. 
1. Oxygenized nitric and muriatic acids dissolve the hydrate 
of the deutoxide of mercury without effervescence ; but if we 
afterwards pour an excess of alkali into the solution, much 
oxygen is disengaged, and the oxide of mercury, which reappears 
at first with a yellow colour, is speedily reduced. 
2. This hydrate is reduced equally when placed in contact 
with the oxygenized nitrate, or muriate of potash. We see it 
pass from yellow to grey, while, at the same time, much oxygen 
is disengaged. 
3. Oxide of gold extracted from the muriate by means of 
barytes, and containing a little of that base which gave it a 
greenish tint, was put, while in a gelatinous state, into oxyge- 
nized muriatic acid. A strong effervescence immediately took 
place, owing to the disengagement of oxygen. The oxide became 
purple, and soon after was completely reduced. 
4. Oxygenized sulphuric, nitric, and phosphoric acids make 
the oxide of gold become at first purple, as well as oxygenized 
muriatic acid; but the oxide, instead of assuming afterwards 
the aspect of gold precipitated by the sulphate of iron, becomes 
dark brown. These experiments seem to tend to show the 
existence of a purple oxide of gold. 
5. When oxygenized nitric acid is poured upon oxide of 
silver, a strong effervescence takes place, owing entirely to the 
disengagement of oxygen, as in the preceding cases. One 
portion of the oxide of silver is dissolved, the otheris reduced at 
first, and then dissolves likewise, provided the quantity of acid 
be sufficient. The solution being completed, if we add potash 
to it by little and little, a new effervescence takes place, and a 
dark violet precipitate falls ; at least, this is always the colour of 
the first deposite. This deposite is insoluble in ammonia, and, 
according to all appearance, is a protoxide of silver, similar to 
what an English chemist has observed while examining the action 
of ammonia on oxide of silver. 
6. Oxygenized sulphuric and phosphoric acids likewise 
partially reduce the oxide of silver, occasioning a strong effer- 
, vescence. 
* Translated from the Ann, de Chim, et Phys, ix. 94. 
