***** To join INSNA, visit http://www.insna.org ***** If one looks up the word 'diffusion' in the *Dictionary of the History of Science*, you get the standard explanation that 'diffusion' originated in the 19th c with Graham and Maxwell and has a Latin etymology in the word, *diffundere*, which means "to spread out." There has to be more to the story than this, right? Earlier references might include the "diffusion of refracted light" in Robert Greene (1727) and "diffusion of light" in Newton's *Optical Lectures* (1728). My question for these listservs is, does anyone have any additional insight into the history and origins of the abstract idea of 'diffusion?' Thank you, Thomas Ball _____________________________________________________________________ SOCNET is a service of INSNA, the professional association for social network researchers (http://www.insna.org). To unsubscribe, send an email message to [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the body of the message.