IODINE 



3031 



ION 



(benzine or gasoline) it forms violet-colored 

 solutions. 



Tincture of iodine used in medicine is made 

 by mixing one-half ounce each of iodine, po- 

 tassium iodide and water and then adding 

 enough alcohol to make up a pint. To pre- 

 vent its staining the skin the tincture is some- 

 times decolorized by adding ammonia. Iodine 

 is used in medicine as a "counter-irritant" to 

 reduce swellings and allay inflammation, an 

 action probably due to its antiseptic proper- 

 ties. It is also used in photography, in the 

 manufacture of dyes and in analytical chem- 

 istry. 



Chemically, iodine is a very active non- 

 metal, closely related to chlorine and bromine. 

 Like these it combines energetically with the 

 metals. Antimony powder thrown into iodine 

 vapor burns spontaneously. Mercury and io- 

 dine warmed together .combine with evolution 

 of much heat. Phosphorus brought in contact 

 with it melts and takes fire. With starch 

 it forms a blue coloration. This affords a most 

 delicate test for either starch or iodine, said to 

 be capable of detecting one part of iodine in 

 ten million parts of water. 



Many of the compounds of iodine are inter- 

 esting. That with hydrogen is a heavy and 

 exceedingly soluble gas (see ABSORPTION), its 

 solution being a strong acid like hydrochloric 

 acid. The iodides of silver and lead, which are 

 yellow substances, may readily be obtained as 

 beautiful precipitates by mixing a solution of 

 potassium (or sodium) iodide with one of silver 

 nitrate or lead acetate. The red iodide of mer- 

 cury can be made not only by mixing solu- 

 tions of potassium iodide and mercuric chlo- 

 ride, but also by grinding these two white 

 solids together in a mortar. Potassium iodide, 

 which is the commonest iodine compound in 

 commerce, is used extensively in medicine. 

 One of its uses is as an antidote for lead or 

 mercury poisoning. Silver iodide is used in 

 photographic dry plates. lodoform, a com- 

 pound with carbon and hydrogen, is used as 

 an antiseptic in dressing wounds. 



Small quantities of iodine compounds are 

 found widely distributed throughout the min- 

 eral and vegetable kingdoms and even in ani- 

 mals. The thyroid gland, situated in the neck, 

 icretes an iodine compound, and in treating 

 diseases due to the ill-development of this 

 land, a preparation from the thyroids of sheep 



used as a medicine to increase the store of 

 lis compound. Certain seaweeds have the 



>perty of absorbing iodides from the sea 



water, in which they are present in such small 

 proportions that they can scarcely be detected 

 by chemical means. For a long time such 

 seaweeds were the chief source of iodine, and 

 a small part of the world's supply is still made 

 from them. The great bulk of the present 

 supply, however, comes from Chile, where 

 iodine is obtained cheaply as a by-product of 

 the purification of sodium nitrate (Chile salt- 

 peter). The Chilean manufacturers have com- 

 bined to limit the export and keep up the 

 price, which steadily advanced from $2.60 a 

 pound in January, 1912, to $4.25 a pound in 

 January, 1916, wholesale in New York. See 

 MEDICINE AND DRUGS. J.F.S. 



IODOFORM, io'dohform, small, yellow crys- 

 tals formed by a combination of hydrogen, 

 carbon and iodine, and having a sweetish odor 

 and unpleasantly sweet taste. lodoform will 

 dissolve in ether, oils or alcohol, and in this 

 form or as an ointment it is used as an anti- 

 septic for wounds and sores. Although it is 

 useful as a disinfectant, less disagreeable and 

 less poisonous substitutes are usually employed. 



IOLA, io'la, KAN., the county seat of Allen 

 County, situated in the southeastern section 

 of the state, and on the Neosho River. Kansas 

 City is 110 miles northeast and Wichita is 100 

 miles west and south. The Atchison, Topeka 

 & Santa Fe, the Missouri Pacific and the Mis- 

 souri, Kansas & Texas railroads serve the city. 

 The town was organized by the lola Town 

 Company in 1859; it became the county seat 

 in 1865 and was chartered as a city in 1898. 

 In 1913 the commission form of government 

 was adopted. The population increased from 

 the official count of 9,032 in 1910 to 11,068 in 

 1916, by Federal estimate. 



lola is a wholesale distributing point for 

 agricultural produce. Following the discovery 

 of natural gas in this territory in 1896, several 

 immense zinc smelters and a number of brick 

 plants were established here. Besides these, 

 there are large Portland cement plants, shirt 

 and overall factories and iron and marble 

 works. lola has a Federal building, in which 

 is located a United States Weather Bureau 

 station, a $50,000 county courthouse, a Y. M. 

 C. A. building, a $15,000 Carnegie Library and 

 several fine churches. In connection with the 

 public schools an agricultural course and a 

 manual training department are maintained. 



I'ON. In electricity ions are minute particles 

 of matter which are oppositely charged. For 

 example, sulphuric acid, which is composed of 

 hydrogen two parts, sulphur one part and oxy- 



