Archived posting to the Leica Users Group, 1999/02/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Robert. Osmosis is the passage of molecules from an area of higher concentration to an area of lower concentration through a differentially permeable membrane (I did learn something in HS science class!). I don't think there is a membrane involved in film, so the explanation (if it is true that distilled water causes swelling and softening) must be elsewhere. Sincerely, Joe Stephenson - -----Original Message----- From: Robert G. Stevens <robsteve@istar.ca> To: leica-users@mejac.palo-alto.ca.us <leica-users@mejac.palo-alto.ca.us> Date: Thursday, February 18, 1999 11:39 AM Subject: Re: [Leica] Re: Diltilled water >Jim: > >I will have to side with Ken on this one. I remember in High School >Biology class we did an experiment on Osmosis in cells. With distilled >water the cells would blow up and some explode. I think it had to do with >the difference between inside the cell and outside. I don't know wheter it >is trying to equalize the salinity or what, but a more knowlegeable person >than me can explain this. The distilled water is so pure, it rushes in >through the membranes of the cell. I think the emulsion is gelatin and >made of cells. This may be the argument that Ken was using. > >Regards, > >Robert > > At 09:58 AM 2/18/99 -0800, you wrote: >>Huh??? >> >>This is a phenomenon that I'm sure science would like explained. >> >>I've used deionized, distilled, and every other type of water in my 53 >>years of darkroom work. And I can assure you that distilled, deionized, or >>any other kind of "normal" water, (except "hot" water,) will "not" soften >>or swell film emulsion. For E3, E4, and E6, I "always" mixed my chemicals >>with distilled water and used a final rinse of distilled water. Likewise >>with B&W. The only real water problem, is that some tap water contains >>chloramines, mineral compounds, and other molecular chemistry that can >>effect the pH of your developer. By using distilled water, or even >>deionized water, your chemistry will perform closer to normal. >> >>Distilled water is just water without the mineral compounds and pollutant >>junk in it. It's clean water. >> >>Use it. >> >>Jim >> >>At 11:34 AM 2/18/99 -0500, Ken wrote: >>> >>>Be careful with distilled water for the final rinse. It will cause the >>>emulsion to swell and become VERY soft! >>> >>>Ken Wilcox >> >> >> >> >> > >