Tyndall Effect (was how do you make WHITE?)

[brian whatcott <inet@INTELLISYS.NET>]

> > I DO recall that one method adopted for measuring particle
> > contamination in liquids was to measure the forward scattering
> > of a laser beam in e.g wine.
> > More or bigger particles led to more scattering, I seem to recall.
> >
> > Brian


At 13:33 3/7/99 -0500, you wrote:
> Sounds like an interesting experiment.  Any more details available?
> Afterwards we could consume the wine.
> This might improve enrollment in physics classes, particularly at my level.
> Br. Robert W. Harris
...


I wish I could recollect more from the little notice that stuck
in my mind, probably from a New Scientist report, or possibly
something in Scientific American.

 I expect the Tyndall effect was the ruling principle, whereby
 particles as small as 10 nanometers can be visualized by the
scattering of visible light transmitted across the field of view.
   This was an observation apparently attributed originally to Faraday.

There was a brief vogue for visualizing sols in the "ultramicroscope"
which operated on this principle.    These mixtures, long out of
fashion, seem to have something to offer for the visualization of
electric fields, composed as they are of numerous charged particles.

I should mention in the same vein as Br. Robert's note, that I recall
an earnest explanation for the occasional instance of clerical
intoxication. It was attributed to the necessity for consuming the
remainder of the aliqot of Blessed Communion Wine,for which substance,
consignment to the sink was sometimes considered infra dig.

 Today, we can certainly say this wine ( in modest amounts) is
twice blessed, for its helpful effects on high blood pressure.

Brian

brian whatcott <inet@intellisys.net>
Altus OK