solution, there are energy changes. It has been estimated that the amount of energy required to ionize 63 grams of copper in a liquid electrolyte is approximately 17,700 calories or 74,340 joules; while, when 65 grams of zinc are ionized, 33,100 calories, or 139,000 joules, are liberated. (63 grams of copper and 65 grams of zinc are ‘equivalent’ amounts.)
ION (ī′ŏn) OF CHIOS, kī′ŏs (c.500-c.422 B.C.). A Greek author, who came to Athens when he was still young (B.C. 478). He was a member of the circle which included Cimon and Pericles, and was probably personally acquainted with Æschylus and Sophocles. His only work in prose, so far as we know, was the Ἐπιδημίαι, reminiscences of celebrated visitors at Chios, which was of great importance to the Greek historians who succeeded him, and has some value for literary history. The fragments of this work may be found in Müller, Fragmenta Historicorum Græcorum (1853). There is also a tradition that he wrote on the colonization of Chios. But his poetry was even more important; he wrote tragedies, lyrics, and elegiac and dithyrambic verse. Consult: Nauck, Tragicorum Græcorum Fragmenta (1889); and Bergk, Poetæ Lyrici Græci (1900).
I′OPHON (c.450-c.390 B.C.). A Greek tragedian, son of Sophocles. We know little of his life or of his plays. There is a statement in Valerius Maximus attributing the Antigone to him. The story that he accused his aged father of insanity so that he might have control of his property, and that Sophocles proved his sanity by reading to the judges from the Œdipus, is unsupported by any evidence. The few verses of Iophon which survive may be found in Nauck, Tragicorum Græcorum Fragmenta (1889). Consult Wolf, De Iophonte Poeta (1884).
I′OS, or NI′O. One of the Cyclades, Greek Archipelago, situated about 13 miles south of Naxos (Map: Greece, G 5). Its area is over 45 square miles and its surface very mountainous. The inhabitants cultivate olives and the vine, and raise cattle. The only town, Ios, has a population of 2000. According to local tradition, Homer was buried on the island.
IO′TA (Lat., from Gk. ἰῶτα, from Phœnician yōdh, Heb. yād, Ar. yad, hand). The ninth and smallest letter of the Greek alphabet, corresponding to the English i.
I. O. U. (I owe you ) . A memorandum of debt or due bill, named from its abbreviated form, viz.:
New York, January 1, 1903.
John Doe, I. O. U. $20.
Richard Roe.
In England and in most of our States, it is not treated as a promissory note (q.v.) because it does not contain an express promise to pay. By statute or by judicial decisions in some States an I. O. U. is declared to be a promissory note. See Due Bill.
IOWA, ī′ō̇-wȧ (popularly known as the ‘Hawkeye State’). One of the North Central States of the United States. It lies between latitudes 40° 30′ and 43° 30′ N., and between longitudes 89° 5′ and 90° 31′ W., and is bounded on the north by Minnesota, on the east by Wisconsin and Illinois, from which States it is separated by the Mississippi River, on the south by Missouri, and on the west by Nebraska, from which it is separated by the Missouri River, and by South Dakota. Its shape is nearly that of a rectangle, measuring 310 miles from east to west and 205 miles from north to south; its area is 56,025 square miles, and it ranks twenty-second in size among the States of the Union.
Topography. Iowa lies entirely within the great central prairie belt. Its surface is a plateau with an average height of 1000 feet in the northwestern corner of the State, the highest point, Waneta in O'Brien County, being 1562 feet above sea-level. The plateau slopes gradually in gently rolling prairies toward the southeast, where its average altitude is about 400 feet. It is only where the rivers have eroded their channels through the glacial drift, forming steep bluffs, and in some places rocky cañons, that the country is at all rugged. The greater portion of its area, though not perfectly level, is so free from natural obstructions that the country roads are laid out in squares, crossing at right angles with the absolute regularity of a checker-board. The State is divided into two hydrographic systems, the eastern two-thirds being drained by the direct affluents of the Mississippi, and the western third by those of the Missouri. The divide between the two systems runs obliquely across the State from northwest to southeast. From this the Mississippi affluents flow all in a southeast direction, and the Missouri affluents all to the southwest. The principal of the former are the Turkey, Wapsipinicon, Red Cedar, Iowa, Skunk, and Des Moines rivers, the last being the largest river within the State. The principal Missouri affluents are the Big Sioux, forming most of the South Dakota boundary, the Little Sioux, the Nishnabotna, and the Nodaway. Many of these streams are navigable for very small craft, but, owing to the railroads, they are unnecessary as waterways and little used. Like all typical glaciated areas, Iowa is dotted, especially in the northern part, with numerous small but often beautiful lakes, several of which are favorite resorts, such as Spirit Lake in Dickinson County near the north boundary, a beautiful sheet of water, 2½ by 5 miles, with picturesque, wooded shores. Forest areas are small in Iowa; they are chiefly confined to the faces of the bluffs along the river-courses. The most common trees are the oak, elm, cottonwood, hickory, and maple, while scanty forests of pine and cedar are found on some of the bluffs. Grasses are the predominating feature of the landscape as well as of the flora of the State.
Climate and Soil. The climate in different parts of the State shows only slight variations, which are due to differences in latitude and altitude. It is of the continental type, with great variations in temperature between summer and winter. The mean annual temperature is 47.4° F., and the extremes recorded during the past decade are -40° and 110°, showing an extreme range of 150°. The average annual rainfall is 30.11 inches, more than two-thirds of which usually falls during the six crop months, April to October. These copious but not excessive rains, coinciding with continued high temperature during the summer months, are, next to the rich soil, the chief cause of Iowa's agricultural prosperity.
Practically the whole of Iowa is arable land. The soil may be divided into three distinct kinds, alluvial soil, glacial drift, and loess. The alluvial soil consists of recent deposits on the bottom
