Osmosis - definition: Spontaneous passage or diffusion of water or other solvent through a semipermeable membrane. If a solution is separated from a pure solvent by a membrane that is permeable to the solvent but not to the solute, the solution will tend to become more dilute by absorbing solvent through the membrane. The pressure caused by the migration of solvent through the membrane is called osmotic pressure. The skin is made up of cells like any other part of our bodies and so are semipermeable. On a cellular level, transport mechanisms occur which allow fluids and other things to cross the cell membrane. Water follows salt (and magnesium), so soaking in a salt solution will draw (edema) fluid out. The water will go to the place of higher salt concentration - even if that is outside the body in a tub or bowl of water. Everything seeks to balance. It's all in the osmosis and cell biology stuff learned in the first semester of anatomy and physiology. I wish I could find my old A&P book though so I could referance it! Any good A&P text would contain this stuff if you really want to understand it thoroughly. Think about topical meds worn in patch form, or creams that are applied to the skin that are absorbed systemically. While absorption can be unpredictable at times and for some patients, many of these meds are well absorbed. Michelle Meeks, RN *********************************************** To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or digest) To unsubscribe: unsubscribe lactnet All commands go to [log in to unmask] The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(TM) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html