410 BOMBTX MORI 



scarcely a trace of bitumen ; and, secondly, when the seam of coal is examined in the 

 neighbourhood of a whin dyke, whore heat has evidently acted on it, it is found 

 nothing like cannel, but as a soft sticky substance, of a brown colour, resembling burnt 

 india-rubber. Besides these facts, the seams of coal and their accompanying strata, 

 both above and below the cannel, show no signs of the action of heat, but, on the 

 contrary, exhibit every appearance of having been deposited in the usual way, and 

 of remaining without undergoing any particular alteration. E. W. B. See CANNEL 

 COAL. 



BOGHEAD NAPHTHA, (syn. Bathgate naphtha), naphtha from the Boghead 

 coal. See NAPHTHA, BOGHEAD. 



BOG-IRON 1 ORE is an example of the recent formation of an ore of iron, arising 

 from the decomposition of rocks containing iron, by the action of water charged with 

 carbonic acid. The production of this ore of iron in tho present epoch, explains to 

 us many of the conditions under which some of the more ancient beds of iron ore 

 have been produced. 



Bog-iron ore is common in the peat bogs of Ireland and other places. See IRON 

 OBBS and IRON. 



BOG MANGANESE. Wad, or earthy manganese. See MANGANESE. 



DOGWOOD. The trunks and larger branches of trees dug up from peat bogs. 

 The black oak of the bogs of Ireland, which is so largely employed in the .manufac- 

 ture of ornaments, is so called. 



BOHEA. A kind of black tea. See TEA. 



BOHEMIAN BOLE. A yellow variety of bole. 



BOHEMIAN GARNETS. Garnets belonging to the mineralogical species 

 Pyropc. They occur embedded in serpentine at Zoblitz in Bohemia, and also loose in 

 the sands of some of the rivers of Bohemia. These garnets are of a rich dark-red 

 colour, and have been largely employed in cheap jewellery. They are cut and 

 polished in mills worked by water-power, and are mounted by working jewellers at 

 Prague. 



BOILED oili. Linseed oil boiled with litharge, which removes some of its olea- 

 ginous parts, and renders the oil more ' drying,' that is, it solidifies more readily. 



BOIXiER. See STEAK BOILER. 



BOIIiER PXiATE. Sheets of iron used for making boilers, and now largely em- 

 ployed for constructing railway bridges, ships, tanks, &c. The average resistance of 

 boiler plates is reckoned at 20 tons to the square inch, and tho weight which they can 

 carry safely is about 5 tons on the square inch. Kiveting is calculated to reduce tho 

 strength to a degree corresponding to that of the area which the rivets occupy. Such 

 are tho principles by which the Kailway Department of the Board of Trade are 

 guided. See IRON. 



BOIS DITRCI. Finely powdered sawdust, and turnings of hard wood, such as 

 rosewood, ebony, mahogany, and tho like, are made into a paste with blood, which is 

 pressed into moulds or formed by dies. It receives a beautiful polish, equal to jet, 

 which it much resembles. This was first introduced to England in 1862 by M. 

 Latry, senior. 



BOIiE. A kind of clay, often highly coloured by iron. It usually consists of 

 silica, alumina, iron, lime, and magnesia. It is not a well-defined mineral, and, con- 

 sequently, many substances are described by mineralogists as bole. Armenian bole 

 is of a bright red colour. This is frequently employed as a dentifrice, and in some 

 cases it is administered medicinally. Bole of Blois is yellow, contains carbonate of 

 lime, and effervesces with acids. Bohemian bole is yellowish red. French bole is 

 of a pale red, with frequent streaks of yellow. Lemnian bole and Silesian bole are, in 

 most respects, similar to tho above-named varieties. The following analyses are 

 by C. Von Hauer. Capo di Bove Silica, 45'64 ; alumina, 29'33 ; peroxide of iron, 

 8'88 ; lime, 0'60; magnesia, a trace; water, 14-27 = 9872. New Holland Silica, 

 38 '22 ; alumina, 31 -00; peroxide of iron, 11 '00; lime, a trace; magnesia, a trace, 

 water, 18'81 = 99-03. 



BOLETUS. A genus of the mushroom order. See AMAuor. 



BOIiOGNIAN STONE. A variety of sulphate of baryta, found in roundish 

 masses, which phosphoresces when, after calcination, it is exposed to the solar rays. 

 Bolognian phosphorus was formerly made from this stone. See BARYTA, SULPHATE OF. 



BOMBASINE. A worsted stuff mixed with silk ; it is a twilled fabric, of which 

 the warp is silk and the weft worsted. 



BOMBTX MORI. The moth to which the silkworm turns. The caterpillar 

 (silkworm) is at first of a dark colour ; but gradually, as with all other caterpillars, 

 it becomes lighter coloured. This worm is about eight weeks in arriving at maturity, 

 during which time it frequently changes its colour. When full grown, the silkworm 

 commences spinning its web in some convenient place. The silkworm continues 



