Farther Bx-perimerds and Olservdtions on Iodine, 359 



may be procured by drop])ing sulphuric acid into a solution of 

 the triple compound of barium ; but the conclusions of tliis in- 

 genious chemist seem to hare been founded upon the want of 

 effervescence in the process ; and his experiments were mada 

 at a very earlv period of the investigation, and probably before 

 this time he lias foimd rea^^on to alter his ojjinion. 



It is probable that a binary compound of iodine and oxygen 

 may be formed, but the facts presented by the action of acids 

 i)n the triple compounds are not sufficient to prove its existence. 



When small quautitic^ of very diluted sulphuric acid are di- 

 gested on the triple conijjounds of potassium and barium, the 

 fluid pbtained is always acid, and ahvays precipitates muriate of 

 baryta. I thought it possible that the compound of iodine and 

 oxygen might possess this property ; but on collecting the pre- 

 cipitate and examining it, it ap])eared to be a mixture of the 

 triple compound and sulphate of baryta, and from ail the facts 

 it appears that in tlie action of acids on the triple compounds 

 new combinations only are formed *. 



I take the liberty of proposing for the triple compounds the 

 names of oxy-Iodes, because, when decomposed by heat, they 

 afford oxygen and iodine. Individually thev may be named 

 from their bases. Thus oxy-potassame, or oxy-iode of potas- 

 sium, will signify the triple comjjound of potassium, oxygen, and. 

 iodine, and oxy-barame, or oxy-iode of barium, will denote th» 

 triple compound of barium. 



2. So7ne Ohserval'wvs on HydroiGnic Acid, and on the Com- 

 pounds procured by means nf it. 



1 . I have generally procured the hydroionie acid which I have 

 used in my experiments by the process referred to in the last 

 section, the action of hydrophosphoric acid on potassame, but 

 I have sometimes employed the gas procured from moistened 

 iodine by phosphorus. 



The hydroionie acid gas is rapidly decomposed by being heated 

 in contact \vith oxygen, and a solution of iodine and hydroionie 



* When silplmric ac'u! is mafic to dissolve as rnucli of the triple com- 

 piund of pota>viu'n !))■ hf;;it as possible, liie mixture conceals by cooling 

 into a yeiloiv tr.uisparcnt Siibstuiicc, extreuicly deliquescent, and very acid. 

 Oil dcconiposin;^ it by lipat, neutral sulphate of pota^sa remains. Now as 

 oxygen and iodine are the only suhstancts driven oft' by heat, it may be 

 asserted that the acid property of the mixture depends upon these two 

 principles; yet this conclusion does not follow aecordinj; to sound che- 

 iiiicul lo<;ic: iodine alone destroys the alkaline properties of potassa, and 

 oxyt;on .-ind iodine in conibination with potassiuui form a diliicultiy soluble 

 and almost tasteless suhstanrc. This substance, the triple compound, has 

 only a weak attraction for sulphuric arid, and it mii;ht be expected that in 

 combining with sulphuric acid it would not deprive it of its acid proper- 

 X.cs. 



Z 1 gas 



