KEY AND INDEX 



was that every organ or part of the body had a corresponding 

 form in nature, whose function was to heal diseases of the 

 organ it resembled. See "Paracelsus," Vol. II, p. 156. 



Siphon Recorder. An instrument for reading cable messages 

 invented by Lord Kelvin in 1867, in the form of a tube of ink 

 so arranged that as the message comes over the wire fine drops 

 of ink are projected upon a piece of paper in lines whose deflec- 

 tions can be made to represent the Morse code. See "The Sub- 

 marine Cable," Vol. VIII, p. 45. 



Sliding Rule. An instrument, used in measuring surfaces and 

 solids, etc., which consists of two graduated and numbered 

 pieces of wood or other material, one of which slides in the 

 groove of the other. 



Solar and Telluric Problems. Problems pertaining to the 

 solar system and to the earth. See "Some Unsolved Scientific 

 Problems," Vol. V, p. 203. 



Sothic Cycle. A period of the Egyptian calendar measured 

 by the heliacal rising of Sothis. See "Astronomical Science" 

 (Egyptian), Vol. I, p. 33. 



Spark Recorder. An instrument used in receiving submarine 

 cable messages, in which a spark is projected against some 

 sensitized surface in an undulating line, which can be read by the 

 operator. See "The Submarine Cable," Vol. VIII, p. 45. 



Spectroscope. An instrument employed in spectrum analysis, 

 perfected by Kirchhoff and Bunsen in 1859. This instrument 

 "discloses the chemical nature and physical condition of any 

 substance whose light is submitted to it." See "Revelations of 

 the Spectroscope," Vol. Ill, p. 62; also, for star-spectra, Vol. 

 V, p. 77- 



Spinning. The process of making thread of uniform size from 

 the fibers of cotton, flax, wool, silk, etc., for weaving purposes. 

 See "An Industrial Revolution," Vol. IX, p. 5. 



Spinning-frame. See Water-frame. 



Spinning-jenny. A machine for spinning invented by James 

 Hargreaves in 1767. See "Hargreaves and the Spinning-jenny," 

 Vol. IX, p. 21. 



Spinthariscope. An instrument devised by Sir William 

 Crookes for examining certain radio-active substances. See 

 "The Nature of Emanations from Radio-active Bodies," Vol. V, 

 p. 102. 



Spontaneous Generation, Theory of. The obsolete doctrine that 

 living matter may originate spontaneously out of non-living 



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