Jeff wrote: > I have noticed some discussion about using microscopy to determine > particle size of CS. ... > In other words, the smallest particle that can be clearly seen in a > light microscope should be about 0.2 microns in diameter.
I've used a simplistic notion to try to predict this. A microscope capable of 1000x magnification (and that's pushing things) would give a .015 micron colloidal silver particle an apparent size of .015 millimeters. In other words, at best the field would be populated by barely discernable dots. I know I'd have a hard time seeing anything in the hundredths of millimeter range! I don't know yet if, even with darkfield techniques, monochromatic light sources, or whatever, we'll actually see individual particles. But, even if the first thing we do is demonstrate that you *can't* directly measure particle size with optical microscopy, that will be useful information. I know for sure we'll want these capabilities as we move from studying the making of CS to its applications. > I happen to have a good light microscope and would be willing to > help you with your research efforts if you would like. I have phase > contrast and dark field condensers and a Sony video camera and > monitor. I can also feed the image into my computer to capture > digital images. Thank you, Jeff. That's exactly the kind of setup Jim and others are working to put together. It sounds like you will be able to help us with the learning curve, as long as you're patient with our inexperience in these things. <grin> Ultimately, I want as many people working together on all of this as possible, so we can back up one another's results. For that reason I don't have any problem with some redundancy in our resources. > I have also used electron microscopes to a limited extent. So have I, Jeff! Incredible tools ... > ... the instruments I have used were very expensive. ... I doubt > that it would be possible for this group to obtain one. I think > your best bet is to contract the work out, which would be much more > cost effective. You're right. Even small SEM's are in the hundreds of thousands range, as far as I know. Then again, you never know what somebody might stumble onto one way or another. A few of us might be able to get a little bit of microscopy done gratis by friends at universities or whatever, but we *will* have to buy some time eventually to do legitimate work. I'd like to follow up with the optical microscopy route if for nothing else than to check samples for gross problems, and possibly to help us develop sample preparation techniques that would work for the SEM. At least one fellow I talked to tried to get some SEM done on his CS. He could only afford to do one test, and the sample was so badly prepared that all he got was clumps. We need to do better. > If I can be of any further help I would be glad to participate in > your research efforts. I have a Ph.D. in soil microbiology and > have conducted research on symbiotic bacteria of agricultural > significance. Unfortunately, I have no experience with bacteria > that are pathogenic to humans. Your background sounds really helpful to me. As long as you won't mind rubbing elbows with the unorthodox among us we'll do just great. An orthodox opinion is just one of many on this list, so don't be surprised by the things people doubt and question. I like to look on that as one of our strengths. I do know it's one of the things that can't be changed! <BIG GRIN> But the part that will not go away, no matter how turned around we sometimes seem, is the people who keep showing up with their stories of how CS has helped them. It will be worth wandering up all sorts of blind alleys if we can get to where we know why and how that happens. When I started looking into CS, the lack of scientific studies and data was (and still is) appalling. I want to try to change that, and we'll have to do it without major funding or support until the results begin to justify it. We're just a bunch of intersted people looking for the truth. I'd be glad of your help. Be well, Mike D. [Mike Devour, Citizen, Patriot, Libertarian] [[email protected] ] [Speaking only for myself... ] -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the subject: line. To post, address your message to: [email protected] List maintainer: Mike Devour <[email protected]>
