[tampora]

I'm trying to devise an experiment. If you've never seen a multi-layer density column, check out this link:

http://www.stevespanglerscience.com/...density-column

I would like to make a density column, similar to this one, with one notable exception. The order of the liquids are: polar, nonpolar, polar, nonpolar, polar, etc.

The purpose of it all is that I'll be shining a polarized HeNe laser down the center of the column. Meanwhile, I'll be rotating the planar polarization of the beam using a half-wave plate. At a specific viewpoint from the column, I hope to see changes in scattering intensity as I rotate the beam, but only for those liquids that are polar.

So far, this is what I am thinking:

Methanol - Polar (792 kg/m^3)
Gasoline - Nonpolar (803 kg/m^3)
??
Vegetable Oil - Nonpolar (920 kg/m^3)
Water - Polar (985 kg/m^3)
??
Honey - Polar (1420 kg/m^3)

I'd like to NOT use gasoline for the risk factor and I doubt my teacher would like the smell of the optics lab afterwords. Do you guys have any ideas for household liquids that would complete or make this column better? For example, the density of methanol and gasoline are so close together, making distinct layers might be difficult. But then again, since one is polar and one isn't, making distinct layers may be easy...

Any thoughts?