Farther Experiments and Observations un Iodine. 303 



In another exj)eviment, in which the sublimate was not dis- 

 solved by water, and in which the absorption was judged of bj^ 

 the admission of fresh quantities of the gas, twenty grains caused 

 the disappearance of 9'G cubical inches or chlorine, the baro- 

 meter being at 30*1, and the thermometer at 5/^ Fahrenheit. 



It seems probable, from these ex>}eriments, that the chlorionie 

 8cid consists of oiic proportion of iodine and one of chlorine. 



The chlorionie acid formed by the sublimation of iodine in 

 chlorine in great excess is of a bright yellow colour, when fused 

 it becomes of a deep orange, and when rendered elastic it form* 

 a deep orange-coloured gas. It is capable of combining with 

 much iodine wlien they are heated together, its colour becomes 

 in consequence deeper, and tiie chlorionie acid and the iodine 

 rise together in the elastic state. 



The solution of the chlorionie acid in water likewise dissolves 

 large quantities of iodine, so that it is possible to obtain a fluid 

 containing very different proportions of iodine and chlorine. 



The pure soUuio)! of the chlorionie acid, when it is very di- 

 luted, loses its colour by Ijeing agitated for some time in con- 

 tact with chlorine, and then, when poured into fixed alkahn* 

 Jixivia or solutions of the alktdine earths, it causes the precipi- 

 tation of substances having tlie characters of trii)le compound* 

 or the oxyiodes. If it is coloured, or in its ordinary state, at 

 the same time tliat the oxyiode is precipitated, much iodine 

 appears, and it is impossible to render a conventraled solution 

 colourless by agitation with chlorine, or to deprive it of its 

 power of yielding iodine by acting on alkaline solutions. The 

 chlorionie acid, when poured into a solution of muriate of baryta, 

 causes a copious .precipitate in it, which has all the characters 

 of oxyiode of barium, and the liquor becomes very acid. 



When the colourless solution of chlorionie acid is added to a 

 strong solution of ammonia, a white powder is precipitated 

 which detonates feebly by a gentle heat ; and which, when de- 

 composed in glass vessels, affords iodine and elastic matter which 

 does not support combustion. 



When highly coloured chlorionie acid is employed, the pow- 

 der that falls down is black, and detonates with much greater 

 force, and by the slightest touch or motion, and it appears to 

 be the same substance as that procured directly by the action 

 of iodine on ammonia, and which I liave shown to l)e a com- 

 pound of azote and iodine. Whether the white powder is a 

 similar substance containing a larger proportion of azote, or 

 whether it is a comjionnd of annnonia with oxygen and iodine, 

 or with iodine and chlorine, I have not yet been able to deter- 

 mine. 



16 



