Boluses

Boluses, see Pills. BOMB CALORIMETER, constructed in its modern form by Berthelot, is used to determine the heat of combustion of organic substances (see Calorimetry), and more recently also for performing certain chemical analyses involving the combustion of the substance being tested in an atmosphere of oxygen under increased pressure. The bomb calorimeter is a thick-walled steel cylinder lined inside with a layer of platinum that protects the walls from oxidation. The cylinder is hermetically sealed with a screw-on or pressure-fitting lid, which has one or two valves for oxygen and an insulated electrode for passing current that heats a thin iron wire and ignites the substance being tested. The latter is placed in a cup attached by a rod to the bomb lid. A fuse wire is also inserted here. After hermetically sealing the lid on the bomb, oxygen is admitted to a pressure of about 20 atmospheres, and the substance is ignited by passing current.

Calorimetry, bomb: a-tube for oxygen inlet; A - fuse wire; b-cup for substance; B - ground glass lid; C - nut clamping the lid; C-electrode; P - platinum lining; d - steel bomb body.

At present, bombs have been produced in which the platinum lining has been replaced by a special enamel, as well as bombs made of special non-oxidizing steel. BOMBYX MORI, the silkworm, a butterfly belonging to the useful insects utilized by man (it does not occur in the wild). The silkworm caterpillar feeds on the leaves of the mulberry tree. Before pupation, the caterpillar releases a silk thread from its silk glands, with which it wraps itself many times, forming a cocoon. The threads of the cocoon, killed in hot water, are unwound by a special method and used to make silk (thread, fabric, etc.). Silk threads have found wide application in surgery, where they are used for suturing wounds. Silk fabrics, distinguished by fineness, strength, lightness, and warmth, also find some technical application in medicine.