426 ISEBLOHN ISINGLASS Rh6ne near Valence, Drome, after a course of 180 in., for more than 80 of which it is navi- gable. The surface of the department in the south is very mountainous, but in the centre and north it frequently expands into extensive plains. There are at least 20 mountain peaks, the lowest over 6,000 ft. high, and the most elevated, belonging to the Pelvoux group, on the border of Hautes-Alpes, over 13,000 ft. The soil of the lowlands is in general very fertile. Agriculture is in an advanced state. The quantity of wine made annually averages over 5,000,000 gallons ; that made in the val- ley of the Rhone has been long celebrated. The production of silk is an important branch of industry. There are mines of iron, cop- per, lead, and coal ; and gold, silver, platinum, zinc, and antimony are found. The staple manufactures are hardware, linens, and cotton yarn. The department is divided into the arron- dissements of Grenoble, Saint-Marcellin, La Tour-du-Pin, and Vienne. Capital, Grenoble. ISERLOHN, a town of Prussia, in the prov- ince of Westphalia, 15 m. W. of Arnsberg; pop. in 1871, 15,763. It is remarkable for its manufactures of iron, steel, bronze, needles, &c. The manufacture of iron was in operation there in the middle ages. That of brass dates from the 18th century. The other manufac- tures are silks, velvet, broadcloth, ribbons, leather, and paper. The country around Iser- lohn is diversified with picturesque ruins, rocks, glens, and valleys. In the vicinity of the town is the celebrated Felsenmeer (sea of rocks), and a remarkable sounding cave containing fossil bones. ISERMA (anc. jtemia a town of southern Italy, in the province and 24 m. W. of the city of Oampobasso, at the foot of the Apennines, and near the source of the Volturno; pop. about 7,500. It is surrounded by a modern wall, founded on the massive remains of an ancient one. In the middle is a fine fountain, with six rows of arches supported on columns of white marble; this, as well as the manu- factories of the town, is fed by an ancient aqueduct hewn in the rock for a long distance and at a great depth. Isernia is the seat of a bishop, has cloth and earthenware manufac- tories and paper mills, and an extensive trade. Until 1780 it was crowded during the September fair with pilgrims to the shrine of Sts. Cosma and Damiano, who were supposed to have ex- traordinary healing powers, and to whom of- ferings were made of red wax models of the parts of the body affected by disease; these finally became so scandalous that the govern- ment suppressed the practice. In 1805 the town suffered severely from an earthquake. isllll Ai;i., son of Abraham and Hagar, born in Mamre. After the birth of a son to Sarah, she persuaded Abraham to banish Ilagar and Ishmael, and from that time Ishmael dwelt as a hunter in the wilderness of Paran. His 12 sons became the heads of 12 tribes dwelling in the Arabian desert between Egypt and the Eu- phrates, under the name of Ishmaelites or Ha- garenes. In the 10th century A. D. the name of Ishmaelites or Ismaelians was assumed by a Mohammedan secret society in Syria and Persia. (See ASSASSINS.) ISIDORE MERCATOR, also called PEOCATOE and PSEUDO-ISIDORE, the supposed author of the false decretals. (See CANON LAW, and DE- CKETALS.) ISI IMIKI S. I. Of Charax, a geographer in the early part of the 1st century. He was the author of a work in which the Greek and Ro- man world and the Parthian empire were de- scribed. There are several quotations in Pliny from this treatise, the extant fragments of which have been repeatedly published in mod- ern times among the remains of the Oeogra- phici Minores. The best edition is that of Miller (Paris, 1839). II. Of Seville, a saint of the Latin church, born in Cartagena, Spain, died April 4, 636. He succeeded to the see of Seville about 600, and was esteemed the most eloquent orator, the profoundest scholar, and the ablest prelate of his ago. In 619 he presided at the second council of Seville, and in 633 at the great council of Toledo. He wrote on science, art, history, and theology; the most curious and important of his works is Orirjinum live Etymologiarum Libri XX., an encyclopedia of all the arts and sciences then known. The best complete edition of his works is that of F. Arevali (Rome, 1797-1803). The fragments of his treatise De Fide Catholica contra Judaeos, after the Paris and Vienna MSS., are given by Karl Weinhold in vol. vi. of the Bibliotliek der altesten deutichen Literaturdenkmaler (Pa- derborn, 1874). ISINGLASS (perhaps from icing glass; Ger. Hausenblase, sturgeon's bladder, isinglass), a kind of edible gelatine, which consists of the dried air bags, sounds, or swimming bladders of fishes. It was known to the ancients by the name of ichthyocolla or fish glue, and is often alluded to by Dioscorides and Pliny. In dif- ferent parts of the world it is obtained from different fishes, and the isinglass of commerce is consequently of various qualities. The best is found among the varieties imported from Russia, particularly that which is brought to St. Petersburg from Astrakhan, and said to be obtained from the sturgeon called the beluga (acipenser huso) of the Caspian sea and the rivers which flow into it, a species which at- tains a length of 25 ft. According to some authorities, the sound is cut open, washed, and then exposed to the air, the inner silvery mem- brane outward. This membrane is then strip- ped off, placed in damp cloths, and kneaded in the hands. Taken out and dried, it forms the leaf isinglass ; folded like sheets of paper, it is the book isinglass; wound in the form of a horse shoe or lyre around three pegs, it forms the varieties known as long or short staple. According to Martin, the inner membrane is removed by beating and rubbing, and the thicker membrane is preserved. The isinglass
