On the new discovered Substance called Iode. 59 
ing water, and has nearly the same volatility as this fluid. By 
no chemical agent does it offer any trace of muriatie acid. The 
iode combines with nearly all the metals ; but’as it is solid, it 
does not appear to develop in its combinations so much heat as 
the oxygenated muriatic acid, with which it has much analogy 
in its general properties, To give an idea of its relations with 
other bodies, we shall compare it with this acid, applying also 
the two hypotheses which have been formed respecting its nature, 
and adding, that on combining with hydrogen it forms a peculiar 
very strong acid, which can be procured inthe gaseous state, 
which is very soluble in water, and which has the same relation 
to iode that muriatic acid has te oxygenated muriatic acid or 
chlorine. The action of phosphorus on iode furnishes the means 
of obtaining the new acid in both its states, gaseous and liquid. 
If we agitate iode and phosphorus together, both perfectly dry, 
‘we obtain a reddish-brown substance which emits no gas; if we 
moisten this substance, it immediately yields copious fumes very 
acid, and at the same time phosphorous acid is formed. We can 
easily obtain the new acid in a gaseous state, by using the iode 
a little moistened ; there is then enough of water to assist its 
formation, but not sufficient to condense it. If we combine the 
iode and phosphorus under water, only a very small quantity of 
subphosphuretted hydrogen gas is disengaged, and the water be-~ 
comes very acid; if the new substance be in excess, the liquid is 
deeply tinctured of a reddish-brown; on the contrary, it is co- 
Jourless if the phosphorus predominates. It generally remains 
in a mass of a red colour, insoluble in water, and in which 
we find some phosphorus and iode. Nevertheless, their propor- 
tions may be such that we can ebtain no residuum, and the li- 
quid may be as limpid as water. li we submit this acid liquor 
to distillation, water comes over, and the new acid does net pass 
into the receiver till the liquid in the retort is highly concen- 
trated: in the latter, pure phosphorous acid remains, which 
soon yields an abundance of phosphuretted hydrogen gas. Thus, 
when phosphorus and iode are dry, a combination analogous to 
that of oxygenated muriatic acid with phosphorus is formed ; 
and when they are moistened, the same phenomenon is produced 
_ as with the liquor of phosphorus poured into the water, while 
the oxygen of the latter with the phosphorus forms phosphorous 
acid, its hydrogen combining with the iode to form the néw acid. 
We now see the characters of this acid: in the gaseous state it 
is colourless, smelling nearly like muviatic gas, smoking when in 
contact with the air, rapidly absorbable by water, giving with the 
oxymuriatic gas a fine purple vapour, and speedily changing over 
mercury: it forms with this metal a greenish yellow substance, 
similar to that which we obtain directly with mercury and the 
vapour 
