of Iodine and Oxygen. 349 



Bv Hcjisid muriatic acid the substance is immediately decom- 

 posed, and the compound of chlorine and iodine is formed. 



When boracic acid was added to a solution of the new com- 

 pound, it dissolved in it by heat, and did not crystallize on cool- 

 ing. Bv evaporation a solid white substance was procured, 

 not so easilv decomposed by heat as the compound itself. 



The taste of all these acid compounds is very sour, though in 

 different degrees of intensity : they redden vegetable blues, and 

 they dissolve gold and platinum. When they are made to act 

 on the alkalies or earths, or on saline solutions which they are 

 capable of decomposing, common neutral salts and oxyiodes are 

 formed at the same time. 



The facts of the combination of the new compound with acids, 

 serve to explain the phaenomena of the action of these sub- 

 stances on the oxyiodes, which I have described in my last paper 

 on iodine, and they confirm the opinions there stated on the na- 

 ture of tins action. The substance procured by M. Gay Lussac, 

 by the action of sulphuric acid on the solution of the oxyiode of 

 barium, and which he has supposed to be a pure combination of 

 oxygen and iodine mixed with a little sulphuric acid, has evi- 

 dentlv for its base the conrbination just now described of sul- 

 phuric acid and the new compound, and, as I have shown, it 

 likewise contains baryta. However minute the quantity of sul- 

 phuric acid made to act on oxyiode of barium, a part of it is al^ 

 ways emplo}ed to form the compoimd acid ; and the residual 

 fluid contains both the compound acid, and a certain quantity 

 of the original salt. 



That this compound acid is a true chemical combination, is 

 evident from the observations already detailed, and from its cry- 

 stalline form. There is everv reason to believe that the pro- 

 jwrtions of its elements are definite. In one experiment I found, 

 that a small quantity of the new compound in being converted 

 into the rhomboidal crystals, gained rathci less than half its ori- 

 ginal weight from the addition of the acid, /'. e. two grains be- 

 came 2'S grains. 



In experiments in which the ])roducts of the decomposition 

 of the compounds from phosphoric and sulphuric acids v/erc 

 collected, the acids disengaged were found in their state of hy- 

 drates, from which it is probable that the crystalline compounds 

 are hydrates, and that the common acids carry their definite 

 proportiori of water into the combination. It is not indeed un- 

 likely that the presence of water is connected with the piipeno- 

 menon of combination, and there is an instance of this kind 

 which I long ago pointed out. Sulphurous acid gas, and nitrous 

 acid gns^ ajipear to have no action on each other, unless water 



be 



