OPTICAL COMPONENTS, AND ANALYTICAL INSTRUMENTS AND OPTICAL INSTRUMENTATION AND ACCESSORIES, NAMELY, HIGH PRECISION WINDOWS AND LENSES; INFRARED SPECTROSCOPY MACHINES; ACCESSORIES FOR SPECTROSCOPY MACHINES, NAMELY, EVACUABLE KBR DIES, MAGNETIC FILM HOLDERS, VIBRATING MILLS, AGATE MORTAR AND PESTLE, EVACUABLE KBR PELLET MAKER, BASIC KBR PELLET MAKER APPARATUS, GRIP PRESS, PERMANENT SEALED CELLS, PRECISION AMALGAM SEALED CELLS, DEMOUNTABLE CELL MOUNTS, VARIABLE PATH LIQUID CELL, X-PATH GAS CELL, 10 CM GAS CELL, 5 AND 10 CM DEMOUNTABLE GAS CELLS, CRYSTALS AND CRYSTAL WINDOWS, SINGLE BEAM ATR DEVICE, VARIBLE ANGLE ATR DEVICE, MULTIPLE REFLECTION PLATE HOLDER, SOLID SAMPLE REFLECTION PLATE HOLDER, LIQUID SAMPLE REFLECTION PLATE HOLDER, ATR REFLECTOR PLATES, REFERENCE BEAM ATTENUATOR, BEAM CONDENSER, SPECULAR REFLECTANCE ATTACHMENT, MICRO ATR REFLECTOR PLATES, AND MIRCO CELLS; LASERS AND PARTS THEREFOR; ACCESSORIES FOR LASERS, NAMELY [ CO2 LASER TUBE, CO2 GAS MANIFOLD, CO2 LASER BALLAST BOX, CO2 LASER SUPPLY, ] ZINC SELENIDE BREWSTER ANGLE, WINDOW MOUNT, LASER CAVITY MIRROR MOUNT, LASER TUBE HOLDER, HELIUM-NEON LASER, POWER SUPPLY FOR HELIUM-NEON LASER, AND PORTABLE HELIUM-NEON LASER; PLANO CONVEX POSITIVE MENISCUS LENSES; NEGATIVE MENISCUS LENSES; CYLINDRICAL LENSES; PLANO WINDOWS; BREWSTER ANGLE WINDOWS; OPTICAL WEDGES AND PRISMS; RETARDATION PLATES; PLANO MIRRORS; PLANO CONCAVE MIRRORS; REFLECTORS AND BEAM SPLITTERS; OUTPUT COUPLERS; OPTICAL FILTERS; LASER BEAM EXPANDERS AND CONDENSORS; OPTICAL TABLES, BENCHES AND MOUNTS; PRECISION POSITIONERS; CRYSTALS AND CRYSTAL WINDOWS; SAMPLING KITS, COMPRISING, PRECISION AMALGAM CELLS, EVACUABLE KBR PELLET MAKERS, AGATE MORTAR AND PESTLE, KBR POWDER, REFERENCE BEAM ATTENUATORS, DEMOUNTABLE CELLS AND MOUNTS; CALIBRATION KITS, COMPRISING, FILM OF POLYSTYRENE, FILM OF POLYTETRAFLUOROETHYLENE-HEXA-FLUOROPROPYLENECOPOLYMER, POLYETHYLENE, AND SEALED AMPOULES