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  • stereoscopic photograph

    Refers to double pictures of the same scene that produce the effect of three dimensionality when viewed through a stereoscope. They were first envisioned in 1832 by the English physicist Charles Wheatstone, who described this as a uniquely photographic art form, since a draftsman could not draw two scenes in exact perspective from viewpoints separated only 2 1/2 inches, which is the normal distance between human eyes necessary for the three-dimensional effect. Wheatstone's mirror stereoscope was not practical for use with photographs, and the invention was not popular until the 1850s, when Sir David Brewster, a Scottish scientist, designed a simpler viewing instrument. The introduction of the collodion process, which simplified exposure and printing techniques, allowed three-dimensional photographs to become a popular craze. They may be daguerreotypes, negatives, or other forms of photographs. For images in the form of photographic prints on cards, use the more specific term "stereographs."

  • stereotaxic apparatus

    Apparatus for a system of three-dimensional coordinates to locate the site to be operated on during brain surgery.

  • sterilisation

    Surgical procedures that make a person infertile i.e. unable to have children.

  • steriliser

    An instrument used to make objects sterile by killing or eliminating agents such as fungi, bacteria and viruses.

  • stertor

    A noisy inspiration occurring in coma or deep sleep, sometimes due to obstruction of the larynx or upper airways.

  • stethometer

    An apparatus for measuring the external movements of a given point of the chest wall, during respiration; also called thoracometer.

  • stethoscope

    A device which is used to listen to sounds produced by the human body. Ordinarily a stethoscope consists of rubber tubing in the shape of a Y.

  • sticker

    Adhesive-backed slips of paper or similar thin material, usually bearing messages or designs.

  • stigmata

    Bodily marks or sores believed to correspond to the crucifixion marks of Jesus Christ.

  • stomach

    J-shaped organ, lying to the left and slightly below the diaphragm in human beings; one of the organs of the digestive system. The stomach produces gastric juices that break down proteins.

  • stomach pump

    An apparatus for removing the contents of the stomach by means of suction. A stomach pumping is performed using a flexible rubber tube that is passed through the mouth and advanced to the stomach. This procedure includes the instillation of a balanced salt solution into the stomach (via the tube) followed by suctioning the fluid out of the stomach. It is an effective procedure in the treatment of toxic ingestions.

  • stone

    A hard solid made of undissolved minerals and found in the kidneys or bladder.

  • stop-watch

    Timepiece, with one or more sweephands that can be started and stopped at will, used for precise measurement of elapsed time. To refer to timepiece that tells the time of day in addition to these functions, use "chronograph."

  • storage jar

    A jar used to store objects or substances.

  • stores van

    A railway vehicle dedicated to the carriage of railway stores between central works and depots and outstations, minor repair facilities, etc.

  • straight edge

    A draughtsman's instrument for ensuring that straight lines are drawn.

  • strainer - culinary tool

    Utensil or device used to retain or hold back solid pieces or particles while a liquid passes through. For bowl-shaped or conical device with perforated or pierced wall used to drain or strain foods use "colander."

  • streptococcus

    A group of bacteria that destroy red blood cells and cause diseases in humans, including scarlet fever.

  • strigil

    A metal or ivory instrument used to scrape skin. Used in ancient Greece and Rome to scrape the skin clear of dirt.

  • stromuhr

    An instrument for measuring the quantity of blood that flows through a blood vessel in a given time.

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