I think the weak nuclear force and Van der Walls force are in the mix also. JOH
-----Original Message----- From: Matthew McCann PE [mailto:mmcc...@franciscan.edu] Sent: Monday, April 12, 2004 4:16 PM To: silver-list@eskimo.com Subject: CS>Brownian Motion Brownian motion is what holds colloids in suspension. Some previous postings indicated that colloids were held in suspension by the mutual repulsion of charged particles, which is not so. Thermal agitation keeps colloids from sedimenting. Incidentally, a gradient of sedimentation could be used to measure the size of the particulates. I don't recommend this method, though, because it probably requires a centrifuge or ultracentrifuge. Matthew
