eachiofan inchshorterthanthedrinkingglasses. To one end of each string,
tie one small crystal of the salts listed above. Tie theotherend of each string
aroundthe middle of a splint. Place the splints across the tops of the glasses so
thatthe crystals aresuspendedabout!inch from thebottomsof the glasses.
Putthe glasses aside until later. When the water has boiled, remove the splints
and fill each glass halfway.AddI teaspoonfulof rock candy to the first glass and
stir. Add I teaspoonfulof rock salt to the second glass and stir. In the same
fashion, add Iteaspoonfulof the remainingcrystals to theremainingglasses
of boiled water.Thenstartall over again in the sameorderand repeatthe
process once, twice, or as often as necessary until the solutionissaturated.
Nowfill each glass with water thatis still boiling, and repeatthe whole pro-
cedure again, until each glasscontainsa supersaturatedsolution.
Slowly lower each string into the glassthatcontainsa solutionof the same
substanceas the crystal tied on the end. Let the splint rest on the rim of the
glass. Place all 5 glasses on the tray and move them to a place where no one will
disturbthem. Allow them to cool. When they are as cool as the room they are
in, move them to a slightly cooler place. Move the whole tray at once and do it
gently, sothatthecontentsof each glass remain undisturbed.After anhour,
move them to a still cooler place, perhaps the refrigerator. Lowering the
temperaturegraduallyand moving the tray withoutdisturbingthe contents
of the glasses is extremelyimportantfor the success of this experiment. Once
thesolutionshave cooled toabout40° F., let themstandfor several days.
Results:There was apointat which eachsolutionbecamesaturated,although
some reached this pointsoonerthanothers. As the solutionscooled, other
crystals, similar to the one on the string, began to form in clustersaroundit.
If you were lucky, you found one large crystal growing steadily larger. No
matter how many crystals formed, all the crystals ofeach chemical were