1. Petroleum ether into petroleum ether
                    2. Milk into petroleum ether
                    3. Colored water into petroleum ether
                    4. Petroleum ether into water 
                    5. Ether into thin layer of ether on top of water
                    6.Colored water into thin layer of ether on top of water

1. Petroleum ether into petroleum ether top

        The purpose of dropping ether into ether (hereafter referred to as ether) was to provide a constant source of comparison for all liquid drop variations.  As expected, the series of drops were remarkably like that of water into water as discussed by Worthington (see Introduction).  Unlike drops of water into water at the same height (~ 6 in), the second droplet of ether always separated from the column.  It may be that the separation of the second droplet is influenced by the fact that ether has a lower surface tension in comparison to water that causes separation even at the low heights at which the ether drops were conducted.  Another reason may be that the ether column by itself is already so thin that separation is inevitable.  Observations on the drop, led to the conclusions that ether into ether drops are no different than the same liquid drops described by Worthington.

2. Milk into petroleum ether  top

        The first variation on an ether into ether drop was the milk into ether drop.  When milk is dropped into ether, a bubble of air is immediately formed.  The sides of the bubble are briefly made of milk.  The milk subsequently contracts to the bottom of the bubble forming a miniature splash within the bubble.  This tiny splash is pulled downward and breaks free of the bubble, descending through the ether into the water and milk solution beneath.  As the milk leaves the bubble, a progression of ripples emanating upwards is formed.  Images of this progression are found in the Still Gallery.  As the milk droplet descends through the ether, the droplet oscillates in shape.
    As the original milk droplet descends, a high column of ether is formed extending higher than a ether into ether drop.  Several droplets separate from the column, to fall into the liquid (as seen in the video clips).
    The overall drop, is reminiscent of both an object into liquid drop and a liquid into liquid drop (of two liquids of similar solubility).  As in object drops, the droplet forms upward ripples when it breaks through the liquid.  Also, the column of liquid does not consist of the original liquid as in similar liquid in liquid drops.  Instead, the resulting column is made entirely of ether.  However, the resulting effects of the drop also resemble similar liquid, liquid drops; a bubble forms which would not form in an object into liquid drop, and the original drop briefly lines the sides of the bubble. 

  3. Colored water into petroleum ether top

    The colored water into ether drop results yielded almost the same results as milk into ether drops.  The only differences were: (1) the column of ether rises lower than the milk into ether drop column, (2) some of the colored water was trapped inside the column, and (3) the original droplet water droplet often separates into multiple drops when descending through the liquid.  The differences between the water into ether and milk into ether drop sequences resulted due to small differences in the composition of milk and water.  Milk is denser than water and so it is not as easily sucked back up into the forming column of ether.  In all other respects, the two drops are the same.

4. Petroleum ether into water top

    The ether drops into water resulted in the formation of an air bubble lined with the ether due to the force of impact.  The ether was then thrown back up into the air in a thin stream as a result of the restoring force of the surface tension from the water; the original ether droplet fragmented into tiny droplets.  When the tiny droplets reached the surface, they caused brief disruptions on the surface and then settled on the surface as a thin film or were caught in a bubble of water.

5. Ether into thin layer of ether on top of water top

    In the ether into a thin layer of ether on top of water drops, it was observed that a shallow depression/air bubble was formed.  Unlike the ether into water drop, the thin layer of ether caused the droplet to merge with the layer.  Thus, the column was very slight and barely protruded from the surface.  Also, a crown was formed by the splash followed by a succession of violent perturbations across the surface.  In this scenario, the surface tensions of both the water and the layer of ether try to restore themselves to the former shape unsuccessfully, instead causing the surface oscillations.

6. Colored water into thin layer of ether on top of water top

    Dropping colored water into a thin layer of ether was similar to dropping ether into a thin layer of ether.  A closed air bubble was formed while the air bubble collapsed, and the colored water separated into two smaller droplets.  Some of the original water was pushed into a short fat column of rising ether while the rest sank to the division line between the layer of ether and water.  The droplets of food colored water were encapsulated in a thin layer of ether because not until a few seconds later does the food coloring mix with the water (not shown in the video clip).  Interestingly, a tiny droplet of ether was jettisoned high above the surface of the water just as the air bubble collapsed.  Following the fall of the column, violent disturbances were created on the surface of the water for the same reasons as discussed above.  

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*Acknowledgement: the loan of the MotionScope camera was provided by Motion CaptureTechnologies (http://www.mctcameras.com/).