> I'm trying to understand an aspect of the simultaneous diffusion > (effusion?*) of several gases through a permeable membrane between two > spaces. Isn't this 'osmosis' ?? Hmm, Wikipedia thinks this is for liquids, but i thought it included gases. http://en.wikipedia.org/wiki/Osmosis -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist