The Christmas tree that science built - hour three

One of the perfectly respectable and upstanding gentlemen of science working in my office decided that our shared room was simply not festive enough. The answer to such a problem was simple: a magic crystal tree. For those not in the know such wonders consist of a cardboard tree, decorations and a sachet of magic liquid. You pour the liquid into a dish and then plonk in the decorated tree, within am hour you start to see fluffy green crystals growing upon the tree branches. And so started epic science arguments about the witchcraft contained within the solution. A little research found out that you can grow these fluffy crystals using a mixture of sodium chloride, ammonia and "laundry bluing".

Knowledge of the ingredients led to further arguments. Sodium chloride crystals don't look like that, they are growing too fast for something containing hydrophilic sodium ions, what is the ammonia for then? And what is this damn "laundry bluing"? Just a dye? Something else?

And that took us to this: http://www.chymist.com/Crystal%20tree.pdf

So they all seem to be somewhat essential. Our final "agreement" was that the solution is a mixture of ammonia and sodium chloride while the cardboard has been soaked in the "laundry bluing" (which it turns out is a colloidal suspension of the Prussian Blue pigment). The green parts have also been soaked in a dye giving is the lovely green crystals.

Of course, there will be further trials. We need to grow some comparison sodium chloride crystals, some with ammonia added and other bits and pieces.

The wonders of Christmas: RUINED BY SCIENCE