Licence: Public Domain Mark
Credit: Manual of qualitative analysis / by Robert Galloway. Source: Wellcome Collection.
200/272 (page 182)
Licence: Public Domain Mark
Credit: Manual of qualitative analysis / by Robert Galloway. Source: Wellcome Collection.
![tinguished from chlorochromic acid, which it resembles in colour. Hypriopie Acip (HI). 460. This acid and its compounds resemble in their pro- perties the corresponding compounds of chlorine and bro- mine. The pure acid is gaseous. It is extremely soluble in water, and the solution, which is colourless, resembles in properties that of hydrochloric and hydrobromic acids ; but it 1s more easily decomposed than the two latter compounds by the substances which have an affinity for hydrogen, and also by those substances which have an affinity for the other constituent, hydrogen being set free—as mercury, for instance. The colourless solution turns speedily to a reddish brown when in contact with the air, owing to the formation of hydriodous acid (HI,) and water. Many of the iodides of the heavy metals are more insoluble in water than the cor- responding chlorides. 461. Subnitrate of mercury throws down from solutions of the iodides a yellowish-green precipitate of suBIODIDE OF MERCURY (Hg,]). 462. Protochloride of mercury throws down a red pre- cipitate of PROTOIODIDE OF MERCURY (Hel), which is solu- ble in an excess of the protochloride or of iodide of potassium. ; 463. Soluble salts of lead precipitate an orange-yellow precipitate of 1opipE OF LEAD (PbI). 464. Iodine, ina free state, forms with starch, even in highly dilute solutions, a purple precipitate: of 1op1pE oF STARCH. If the iodine is in a state of combination with hydrogen or any metal, it is necessary to liberate it before applying the starch test. 465. Nitrie acid liberates iodine from its hydrogen and](https://iiif.wellcomecollection.org/image/b33169718_0200.jp2/full/800%2C/0/default.jpg)
