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You can learn to judge the relative concentration and purity of your solution by viewing the back-scatter of a laser beam as it passes through your finished solution. It’s known as the Tyndall/Rayleigh effect. You can buy a laser pointer that will demonstrate this for about $30. at a discount computer store. You’ll need a 1 to 5 milliwatt laser diode pointer of 630 to 670 nanometer wavelength. The unit looks like a fat ink pen with a shirt pocket clip. This is a true laser pen. Don’t confuse it with a mere “light emitting diode”.

Shine the laser beam through your solution and view it from about a 15 degree angle. Never point a laser pointer pen directly into anyone’s eyes. It can cause injury. Point the beam through the glass containing your solution, and let it hit the wall or some other non-living surface. Observe the portion of the beam that is running through the solution. The greater the back scatter (the more ‘solid’ looking the beam appears), the denser is the concentration of silver particles. With practice, you can become quite adept at judging relative concentration.

This information is for educational purposes only and is not to be construed as medical advice. Consult the physician of your choice for medical care and advice.

Offered by Ed