and Observations on Iodine, ^oi 
low, that a proper degree of heat cannot be applied to render 
it dry. 
When two bodies so similar in their characters and in the 
compounds they form, as iodine and chlorine, act upon sub- 
stances at the same time, it is difficult to form a judgment of 
the different parts that they play in the new chemical arrange- 
ments produced. When I found that the chlorionic compound 
formed a strong acid by solution in water, I at first suspected 
that water was decomposed and hydroionic acid and euchlo- 
rine formed; there was no effervescence in the process, and the 
proportions agree with the supposition ; but I find that solu- 
tion of euchlorine instantly decomposes hydroionic acid and 
precipitates iodine, which is afterwards redissolved by the 
chlorine set free ; and nitric acid, which decomposes hydroionic 
acid, has no action on chlorionic acid. 
It was possible likewise that if water was decomposed, 
muriatic acid and a compound of iodine and oxygene might 
exist in the solution; I endeavoured to ascertain if this was the 
case by distilling the solution at different temperatures and 
collecting the products, but I obtained always the same fluid. 
When coloured solution of chlorionic acid is boiled with 
hyper-oxymuriate of potassa, it loses its colour, and chlorine 
is given ofFfrom it; but in this case it likewise gradually loses its 
acidity, and a substance which yields iodine by heat with much 
effervescence, and which is probably oxypotassame, is pre- 
ci pitated. 
It appears to me most probable that the acid property of the 
chlorionic compound depends upon the combination of the two 
bodies ; and its action upon solutions of the alkalies and the 
earths may be easily explained, when it is considered that 
chlorine has a greater tendency than iodine to form double 
MDCCCXIV. 3 T 
