Abstract: A sealing composition is provided for joining crystalline ceramic or cermet parts, e.g. in an arc tube for a discharge lamp. The sealing composition comprises, as starting materials, a mixture of alumina (Al.sub.2,O.sub.3), silica (SiO.sub.2) and magnesia (MgO), the mixture comprising in the ranges of from 22% to 24.5% by weight of Al.sub.2 O.sub.3, from 45.5% to 49.5% by weight of SiO.sub.2, and from 26.0% to 32.5% by weight of MgO. The sealing composition contains less than 40% by weight, of the mixture, of the crystalline phase .alpha.-Cordierite when subjected to the following test procedure.(i) sintering the mixture at 1200.degree. C. for 10 hours to produce a friable lump which is crunched and heated at 1550.degree. C. for 2 hours while the glass is in a molten condition;(ii) pouring the resulting material into water to form a brittle frit and, after drying at 160.degree. C., grinding the glass to a powder particle less than 180 .mu.

Abstract: An arc tube for a high pressure discharge lamp comprises a sealing element displaced from the end and sintered within the arc tube to form an overhung end. An electrically conductive cermet end member has a boss member which fits within a central aperture in the sealing element to thereby centralize the cermet end member within the arc tube. The cermet end member is therefore positioned within the arc tube independently of the arc tube wall and any distortion of the arc tube which has taken place during sintering of the sealing element has no effect. Preferred dimensions of the components are given so that cracking of the cermet end member is avoided and suitable electrical resistance is achieved.

Abstract: An electrically conducting cermet for use in a closure assembly in a high pressure sodium discharge lamp which cermet comprises a sintered compact of refractory oxide granules and a conducting network extending throughout the cermet wherein said network is provided by a layer of niobium and, optionally, at least one other specified metal. The cermet is, because of the niobium content of the metallic network, permeable to hydrogen and lamps incorporating this cermet can therefore be stabilized in acceptable times.

Abstract: An apparatus and method for spray application of a burn treating agent is disclosed. The apparatus delivers substantially all of the treating agent from a flexible source thereof through a spray nozzle, preferably without bringing the agent into contact with ambient air or contaminants. In a preferred embodiment, silver sulfadiazine cream is sprayed on a burn wound by urging the cream toward an outlet in a collapsible bag in which the cream is disposed by means of pressure applied to the exterior surface of the bag and conveying the cream from the outlet to a sanitary spray nozzle by means of a compressed air operated sanitary pump.