HEAVEN 494 HEBEON air is necessary to the well-being of the animal body, because one-fifth of the air consists of oxygen and it is upon oxygen that the heat and energy of the body depends. When fuel burns, carbonic acid gas is produced. The same gas is con- tained in the breath from the body, and to produce this carbonic acid, oxy- gen is absorbed from the surrounding air. An excess of carbonic acid in the air produces headache, depression and even nausea, and anything in excess of six parts per ten thousand is liable to cause discomfort. A gas burner, in a small room, will very quickly pollute the air, and for every cubic foot of gas con- sumed, eight cubic feet of air are ex- hausted of their oxygen. It is estimated that one person requires 3,000 cubic feet of air per hour. That is to say, a room 30 feet long, 10 feet high and 10 feet wide contains sufficient air to supply one per- son for one hour, but it is clear that no one could live in a hermetically sealed room of such a size for that length of time without suffering from poisoning, because throughout the time he would be polluting the air and the pollution would pass the safe limit very soon. In the ordinary room, of course, there is constant leakage of bad air and ad- mittance of pure air through cracks and in the doors and windows, through the chimney and by other accidental means. In actual practice, it is found that 250- 300 cubic feet per person in dwellings and factories is sufficient. HEAVEN, in theology, the place or state of the blessed., HEBREW, the character in which the Hebrew language is now written. This, called the square character, was not the earliest. The general opinion is that it came into use only in the centuries im- mediately preceding the birth of Christ, or even about the commencement of the Christian era itself. The character on the Maccabee coins is like the Samaritan, rather than the square Hebrew one. HEBREWS. EPISTLE TO THE, one of the most important epistles of the New Testament. Clement of Rome re- ferred to it about A. D. 96, as did Justin Martyr in the 2d century, followed in due time by many other Christian fathers. The Greek fathei's generally attributed the epistle to St. Paul; the Latin Churches in Europe and northern Africa were long of a different opinion, but by the commencement of the 4th century the Eastern view largely pre- vailed, in the West as well as in the East, and by the commencement of the 5th century it was everywhere dominant. Jerome and Augustine had much in- fluence in giving it currency, which it retained to the Reformation. Erasmus, Cardinal Cajetan, Luther, Calvin, Beza, and others revived the old doubts. The Council of Trent gave a decision in favor of St. Paul, but in Pi'otestant countries the question is still held to be a debatable one. HEBRIDES (heb'ri-dez), a large group of islands, 500 in number, situated of the W. coast of Scotland, of which 100 are inhabited. They comprise, in all, an area of about 3,000 square miles. Among the larger and more notable of these are Skye, Eigg, Mull, lona, Staffa, Ulva, Lismore, Islay, and Rum, the largest being Skye, of the inner Heb- rides, that lie nearer the coast; and Lewis, Harris, Northern and Southern Uist, Barra and Benbecula, of the outer Hebrides, lying farther W., and sep- arated by the strait and channel of Minch and Little Minch from the inner group, the largest being Lewis and Harris, really forming but one island but belonging to two counties. These islands are for the most part rocky and infertile, but well adapted to grazing purposes, the chief industry being the pasturing and rearing of live stock. The islands have been developed and im- proved by the building of good roads, and the establishment of frequent com- munication with Glasgow by steamship. The moors and fens abound in winged game, hare, etc., and are visited by sportsmen in great numbers, being largely and profitably rented for sporting- purposes. The islands are a resort for summer tourists on account of their picturesque scenery. The fishing in- dustry is considerable. Pop. about 100,000. HEBRIDES, NEW, a group of is- lands in the South Pacific, discovered by Quiros, in 1506. Captain Cook, who surveyed most of them in 1773, gave them their name, as being the most W. of the islands of the Pacific. They extend over 375 miles. Area, 4,200 square miles. The soil in the valleys is fertile, but the islands are mostly mountainous, and some have active volcanoes. Since 1887 the group is under a mixed French and English commission. Pop. about 75,000. HEBRON (he'bron), one of the oldest cities in Palestine, belonging to the tribe of Judah, 21 miles from Jerusalem. It was anciently called Kirjatharba, and at a later period was the seven years' resi- dence of King David before he conquered Jerusalem. The modern town, El Khalil ("the friend"— of God, Abraham). Pop. (1919) 22,000. It lies low down in a narrow and picturesque valley— the
