Show attraction and repulsion get a saucer of water a luuie of sugar u small piece of soup seal and a of bits of matches ches or toothpicks uno and you ure tire ready for an interesting te experiment first place some of the bits of wood in the water in the saucer so they will float we will call them boys now drop the piece of soup in the water waiter among adiong the boys and see how they will run away from it hoys boys dont litte like soap you understand NUM now take a fresh saucer of water and drop some new match bits into it and cull call them girls next drop the piece of sugar into tile the water and see se how the girls will w run to it because it Is sweet Ier hup you would like to inua kni wily why the little bits jot wood behe behave so differently ferent ly in the two cases without going into deep scientific ns the long tind and short of it Is that tile the sour soap in dissolving causes an oily film to spread over the surface of tile the water arid n nu this uni film in III radiating from the center carries the sticks with it the sugar in dissolving acts in a different way tile he dissolved sugar being heavier than the water settles to the bottom causing a slight current to werd the center of tile the saucer from tile the edges and carrying the sticks with it this action in elther either case soon ceases pathfinder |