I hadn't seen one of these for decades, but recently found the trick again.  It is the Chu's Magic version of Father Blantz's Liquid Penetration effect. As Chu's frequently did, they shrunk down a larger stage effect to small proportions, but they retained a fairly high quality of production.  

The effect is highly visual and very baffling.  Three small empty glasses are shown to be separate (they really are) and are stacked one atop the other, into a stack of three.  Magi shows three other glasses or small carafes (use your own) each containing a different colored liquid, red, yellow, green.   The red liquid is poured into the top of the stack, and the top glass begins to fill.  No surprise. 

But switching to the green liquid, the magician pours it into the top of the stack, and it somehow pewnetrates all the way down to the bottom glass.  Finally, the yellow is poured and magically filled the glass in the middle!  Very magical.   This prop is small -- the glasses are only about 3 inches tall -- so it is offered here more as a collector's item, as I think it is too small to perform in a stand-up setting, though a younger beginning magician could show it off in a small living room show.  (See related items for a larger version of the effect that is currently being manufactured.) 

This Chu's effect is still sealed in original box.