BITUMEN BJORLING 673 tinct bodies may be separated. Water dis- solves nothing. Anhydrous alcohol dissolves a yellow resin equal to ^ of the weight of the asphaltum ; this is soluble also in ether. The residue, insoluble in alcohol, treated with ether, yields a dark brown resin, which is separated by evaporating the ether. It amounts to -f'y the j weight of the asphaltum. It dissolves easily j in volatile oils, and in oil of petroleum. The ; latter also, as well as turpentine oil, takes up ! tho residue which the ether leaves. The fol- lowing formulas, exhibiting the composition of petroleum and asphalt, are given by Dr. Mus- pratt, as setting forth in a striking manner the derivation of the latter by oxidation of the former : Naphtha, or petroleum C 90 H,,,or C 10 H S ., Asphalt, or bitumen C 40 H 3a O, Great expectations have been entertained of the important uses to which the natural bitu- j mens might be applied ; they have proved to be j admirably adapted for the construction of walks, terraces, roofs, and every kind of hydraulic j work. The material most successfully employ- ed in France for producing the bituminous mastic is liquid bitumen mixed with a bitu- minous limestone, which is ground to powder, sifted and stirred into the boiling asphaltum, four parts of the stone to one of the bitumen. Dry, common limestone, or broken bricks, will answer as well. The mixture, when of homo- geneous consistency, is poured out upon a table covered with sheets of paper, and upon which a square frame is placed for receiving the sheets of mastic. It is spread smoothly by a heated iron roller, sprinkled with sand, and left to cool. When laid, they are united by soldering with a hot iron. Goal tar is often substituted for the natural bitumen, but it is considered far inferior to it in durability and strength. The bituminous limestone is found at Val de Travers, in the canton of Neufchatel, in the Jura limestone formation, corresponding to the English oolite. It consists of 80 per cent, car- bonate of lime and 20 per cent, of bitumen. It is tough, difficult to break with a hammer, and is excavated by blasting. Slightly heated, it exhales a fragrant odor, quite different from that of the factitious compounds. The carbo- nate of lime is so protected by the bitumen that it does not effervesce with muriatic acid. In any artificial mixture it would be impossi- ble to produce so intimate a combination of these substances as is found in this natural asphalt rock. Silicious matters, as sand and smooth pebbles, are not so well adapted for the preparation of durable mastic as calcareous sub- stances, because they have little attraction for the bitumen, and the mixture is liable to crack and crumble. Bitumen is applied also in the form of an external coating of mastic to give strength and protection to thin sheet-iron pipes and glass tubes used for conveying water, also for roofing. To some extent asphaltum may be used as a fuel, especially for heating meters in gas works, when blown into the grate in the form of powder. It appears to have been a principal ingredient in the destructive Greek fire. (See GREEK FIBE.) Bricks of poor qual- ity saturated with it are rendered strong and impervious to water. It answers most of the purposes for which coal tar is used. It makes the strongest cement for laying brick and stone work. The ancient Egyptians used some form of it for embalming bodies. The hardness of the mummies is probably owing to the combi- nation of bitumen with the animal substances. In France a process has been patented for spreading fluid bitumen upon canvas sheets or netting and passing it between metallic rolls, thus coating the cloth on one or both sides, and to any desired thickness. The use of the ma- terial is for lining buildings. -The origin of the bitumens has been regarded as very doubtful. The c.omposition would seem to refer them to vegetable matters, though they possess very marked differences from the coals. BITUMINOUS SHALE, a soft variety of argil- laceous slate, found usually associated with coal. It contains a variable proportion of bitumen, sometimes so much of it that it will burn. In Mansfeld, Germany, the bitu- minous schist found immediately over the new red sandstone contains also a small quan- tity of copper pyrites, and though it yields only 1$ per cent, of metal, it is made to pay a profit by the ore furnishing its own fuel for reduction. Shale is sometimes distilled for paraffine and illuminating oil. BITZItJS, Albert, a Swiss author, better known under the pseudonyme of Jeremias Gotthelf, born at Morat, in the canton of Fribourg, Oct. 4, 1797, died at Lutzelfliih, in the Emmen val- ley of the canton of Bern, Oct. 22, 1854. In early life he officiated as pastor in Bern, and for some time took part in politics; but from 1837 till his death he devoted himself ex- clusively to literature. His writings consist chiefly of tales descriptive of the home life of Switzerland. A complete edition of his works in 24 vols. was published at Berlin, 1855-'8. He also published several popular almanacs. BIZERTA, or Benzerta (anc. Hippo Zarytus), a fortified seaport town on the N. coast of Tunis, the northernmost town of Africa, on a gulf which communicates with a lake in the interior ; pop. about 8,000. The harbor was formerly commodious, but is now choked up with sand, and receives only small ves- sels. The adjoining lake abounds in fish, the roes of which, dried and formed into a sub- stance called botargo, are an article of Medi- terranean commerce. BJORLING, Carl Olaf, a Swedish prelate and author, born at Westeras,' Oct. 17, 1804. He is a graduate of Upsal, and became a teacher of mathematics and afterward of history. He was ordained in 1844, was promoted to the deanery of Westeras in 1852, and in 1866 he was consecrated bishop of that diocese. The principal of his various learned works (in La-
