wow … this is cool.
“It’s a bottle full of magic liquid that’s said to be able to actually forecast the weather.
The liquid has certain properties that create various types of crystals that correspond with approaching weather. For instance, if the liquid takes on a milky appearance, it will soon rain. If the liquid’s clear, that predicts nice weather ahead, and fern-shaped crystals predict windy weather.
Its makers say it was “discovered hundreds of years ago by the early alchemists,” but we’re at a loss to figure out how this $110 tube of goo works, if it does at all. If it doesn’t, at least it can be a fascinating conversation piece, and also amaze you with its growth of various weird-looking crystals.” …. from gizmodo.com