… electrically charged plates or coils carrying a current); these act as condenser, objective and projector. … (3) The specimen stage. (4) The vacuum pump unit which maintains a vacuum in the electron tube; these are sometimes self‑contained units connected to the appliance. (5) The elements …
… articles may be made of various materials and they may contain natural or cultured pearls, precious or semi‑precious stones (natural, synthetic or reconstructed), precious metal or metal clad … with precious metal provided these latter materials are present as minor components only . Otherwise they fall in …
… dimensions than are building bricks. Whereas bricks play an essential part in constructional work, forming the very … of the building, flags and tiles are more especially intended for fixing by cement, adhesive or by other means to the surface of …
… the same family as the cochineal and the kermes. The most important commercial varieties are the following : (A) … put up in the form of twisted hanks. The sap of certain oriental trees which hardens, forming a resistant film when exposed to air (known as “Japan …
… may also be extracted from greasy wool by means of volatile solvents (carbon disulphide, etc.). Wool grease does not … wax rather than a fat. It is employed in the preparation of lubricants and for other industrial purposes, but it is … by purifying wool grease, has the consistency of an ointment; it ranges in colour from yellowish‑white to brown …
… the same film. They have an optical system which consists essentially of a light source, reflector, condenser and … have a mechanism, generally consisting of a maltese cross movement, which draws the film intermittently past the optical system, usually at the same …
… raw hides and skins with the hair or wool on of animals mentioned in Note 1 (c) and referred to in the Explanatory … the hide or skin for splitting operations and temporarily prevents putrefaction. Hides and skins thus processed … 41.04 to 41.06) . Tanning renders the hides and skins resistant to decay, and increases their impermeability to …
… 2828.90 ‑ Other Subject to the exclusions specified in the introduction to this sub‑Chapter, this heading covers … calcium hypochlorite. (A) HYPOCHLORITES These are the most important; they are mainly used for bleaching (“bleaching … deteriorate in the air; they give hypochlorous acid on contact even with weak acids. Hypochlorous acid, readily …
… : (1) Mercury oxides . Mercuric oxide (HgO) is the most important oxide of mercury. It can exist as a bright-red … to light. They are used in the preparation of marine paints or mercury salts, and as catalysts. (2) Mercury … white needles. Soluble in water (especially when hot); a violent poison. It is used for “bronzing” iron, for …
… transparent and odourless; toxic. Used as a bleaching agent for textiles and for hides, as a mordant in the textile industry, and in organic synthesis. Its main salts are ammonium, potassium, …
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