Simon writes: > 1. I am still having trouble fully understanding the Tyndall effect.
You seem to understand it's basic use as far as CS is concerned. You used it to confirm there was still *something* in the water after leaving some CS in the sun for a while! <smile> For our purposes, the Tyndall effect is just the scattering and reflection of a beam of light from small particles and/or droplets that cause you to be able to see the beam's path visualized. Examples: dust and water droplets in the air allowing you to see "rays" of sun coming through the clouds; a flashlight beam in a smoky room; your laser pointer's beam in a glass of CS... Exactly how it applies to your CS depends on the process you're using to make it and the kind of CS you're attempting to make. A lot of us nowadays are using some sort of current limiting and/or large surface area electrodes to keep the current density in the low microamps per square centimeter range, in hopes of producing a relatively high proportion of ions versus particles, and keeping the particles we do get as small as possible. In this kind of system you'd expect the Tyndall effect to be very weak, needing a dim room to even see it. The product would tend to be colorless as well, both because of the low concentration of particles and because the size of particles produced would absorb only those frequencies of light toward the UV end of the spectrum, and thus continue to reflect or scatter all the visible wavelengths. If you kept going long enough for the particles to start agglomerating and growing bigger you'd eventually see a straw, yellow, golden, or even reddish brown color, the intensity depending mostly on the density of particles and the color on their size. It would have a stronger and stronger Tyndall effect, and even begin to appear "milky" in ambient light, as if you'd added a few drops of cream to a cup of tea -- still transparent, but with a slightly milky look in bright light. Other ways of producing CS will do different things to the Tyndall effect. Heating the water is suggested sometimes to speed things up. This will get you to the golden and darker brews more quickly, with a strong Tyndall and milky look. Other systems use some kind of mechanical or thermal stirring to keep the particles from agglomerating. If the current is not otherwise controlled or limited, this moves you toward the clear to slightly colored product with mild to moderate Tyndall, depending on how long you run. Finally, the primative "pinch of salt for starter" recipes produce very large particles quickly, the process ending within minutes while putting on a great show of bubbles and churning. The product is clear to milky with a strong Tyndall effect -- at least until the particles start to settle in a muddy deposit at the bottom of the bottle after a few weeks. In the end, use Tyndall effect as a rough guide to the size and density of particles you're producing, bearing in mind that it does not reflect anything about the ionic portion of your product, pun intended. Aside from all of this, sometimes you'll see what we call "sparklies" in the beam. These can be particles or flakes of silver that have grown big enough to be seen due to some irregularity of the process, or other contaminants like dust, lint, dandruff, or whatever. A few sparklies isn't the kiss of death, but more of a reminder to keep things clean and use a covered container -- and not to push your process so hard. Low ppm is just fine. You simply have to use more for the same effect. Some of the stranger experiments people have run can produce a lot of sparklies, however, such as putting Hydrogen Peroxide in *before* the beginning of production. That, I'm told, produces something like the stuff they use in metal flake paint! So don't do it, I guess. Hope that helps. 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. Instructions for unsubscribing may be found at: http://silverlist.org To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
